user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: what character did brian austin green play on 90210? 
Knowledge Triplets: Brian Austin Green, people.person.gender, Male
m.0k94mzg, tv.regular_tv_appearance.series, Beverly Hills, 90210
Brian Austin Green, people.person.profession, Television producer
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.02t926d
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0k94mzp
m.0220tfg, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 0, tv.tv_series_season.episodes, Beginnings With Darren Star (Season 1)
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0k94m_9
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.02t8mh8
m.09w708c, common.webpage.resource, Lori Loughlin, Shenae Grimes join '90210' spinoff
'90210' casting: There's an APB out on Joe E. Tata!, common.resource.annotations, m.09w753y
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0k94myp
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wyb_dp
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tdl
m.0220tdl, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tf6
Babe Alert! '90210' spinoff lands AnnaLynne McCord, common.resource.annotations, m.09w6vvh
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0k94mzp
'90210' officially joins CW's fall schedule, common.resource.annotations, m.09w72tc
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wybzrz
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.02t94lh
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tdz
Beverly Hills, 90210, tv.tv_program.regular_cast, m.02t8mh8
90210Logo, common.image.appears_in_topic_gallery, Beverly Hills, 90210 franchise
m.0220tg2, tv.regular_tv_appearance.seasons, Beverly Hills, 90210 - Season 1
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0k94myw
m.09ym6z8, common.webpage.resource, '90210' recap: Fun with stalking!
m.02t8mh8, tv.regular_tv_appearance.seasons, Beverly Hills, 90210 - Season 1
m.09w722r, common.webpage.resource, '90210' casting alert: Tori Spelling is in
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.0220tfq
'90210' soundtrack lineup announced: OK Go, Adele, N.E.R.D., and more, common.resource.annotations, m.09wn2jv
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.02t94lh
m.0k94m_1, tv.regular_tv_appearance.seasons, Beverly Hills, 90210 - Season 9
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tc8
Brian Austin Green, tv.tv_actor.starring_roles, m.0220tgk
Darren Star, fictional_universe.fictional_character.character_created_by, David Silver
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wyc6zz
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0220tdl
Brian Austin Green, freebase.valuenotation.is_reviewed, Date of birth
m.0k94mzp, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tg2
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tg2
Brian Austin Green, people.person.profession, Actor
'90210' Spinoff: Jennie Garth Is In!, common.resource.annotations, m.09w72ck
m.09w70bt, common.webpage.resource, '90210' spinoff: We have a matriarch!
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wybzrz
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wyc1rh
m.0220tf6, tv.regular_tv_appearance.series, Beverly Hills, 90210
m.09w72tc, common.webpage.resource, '90210' officially joins CW's fall schedule
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.0220tdl
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.0220tgk
m.09w6p61, common.webpage.resource, 'Beverly Hills 90210' spinoff casting begins: Dustin Milligan tapped for pilot
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wyc6zz
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0wybzrz
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.02t8pzz
Brian Austin Green, freebase.valuenotation.is_reviewed, Place of birth
Beverly Hills, 90210 - Season 9, tv.tv_series_season.episodes, That's the Guy
Beverly Hills, 90210, tv.regular_tv_appearance.series, m.0220tgk
Beverly Hills, 90210 - Season 3, tv.tv_series_season.episodes, Shooting Star/American in Paris
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0220tdz
m.09wn2jv, common.webpage.resource, '90210' soundtrack lineup announced: OK Go, Adele, N.E.R.D., and more
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.02t94lh
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tc8
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0c6nwx3
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0k94mzp
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.04hbn5w
Beverly Hills, 90210 - Season 10, tv.tv_series_season.episodes, Eddie Waitkus
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tdl
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.04fgn00
'90210' spinoff: We have a matriarch!, common.resource.annotations, m.09w6_7j
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0k94myw
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0pxmd1c
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0220tdz
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tc8
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tc8
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0k94myw
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0220tc8
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tdl
Beverly Hills, 90210, tv.tv_program.regular_cast, m.04fgn00
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0220tf6
m.0220tfq, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0k94myw
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wybz18
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wyc5nx
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tfg
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tgk
m.02t94lh, tv.regular_tv_appearance.series, Beverly Hills, 90210
m.02t926d, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0220tdl
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0k94mzg
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.02t926d
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tfg
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wyb_33
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0k94myp
m.02t8mh8, tv.regular_tv_appearance.seasons, Beverly Hills, 90210 - Season 3
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.09_0b70
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0wyc1rh
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tgk
Brian Austin Green, people.person.nationality, United States of America
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.02t8mh8
Brian Austin Green, freebase.valuenotation.is_reviewed, Country of nationality
Beverly Hills, 90210 - Season 1, tv.tv_series_season.episodes, The Green Room
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 0, tv.tv_series_season.episodes, A Look Back With Charles Rosin
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.0220tfq
Darren Star, tv.tv_program_creator.programs_created, 90210
'90210' spin-off: Rob Estes joins cast, common.resource.annotations, m.09w72dx
Brian Austin Green, tv.tv_director.episodes_directed, The Final Proof
m.0220tgk, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tc8
m.0220tc8, tv.regular_tv_appearance.series, Beverly Hills, 90210
m.0220tdz, tv.regular_tv_appearance.series, Beverly Hills, 90210
'Beverly Hills 90210' spinoff casting begins: Dustin Milligan tapped for pilot, common.resource.annotations, m.09w6p61
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tg2
Beverly Hills, 90210 - Season 9, tv.tv_series_season.episodes, Brandon Leaves
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tg2
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.02t8d0c
m.09w6_7j, common.webpage.resource, '90210' spinoff: We have a matriarch!
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0k94myp
Brian Austin Green, freebase.valuenotation.is_reviewed, Gender
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.02t8gyb
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tgk
m.02t926d, tv.regular_tv_appearance.seasons, Beverly Hills, 90210 - Season 4
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.04hbn5w
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0220tc8
Beverly Hills, 90210 - Season 6, tv.tv_series_season.episodes, Must Be a Guy Thing
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0wyb_33
'90210' casting alert: Tori Spelling is in, common.resource.annotations, m.09w722r
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0k94m_1
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tdz
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.02t94lh
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wyb_dp
m.02t8pzz, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.0220tc8
'90210' alums: Sad, lonely, and single, what gives?, common.resource.annotations, m.09ycr9w
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0k94myp
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 2, tv.tv_series_season.episodes, Play It Again, David
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.02t8d0c
m.09w72ck, common.webpage.resource, '90210' Spinoff: Jennie Garth Is In!
m.09w72dx, common.webpage.resource, '90210' spin-off: Rob Estes joins cast
m.02t8mh8, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.02t8d0c
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210 - Season 1, tv.tv_series_season.regular_cast, m.0220tfg
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0wyb_33
Beverly Hills, 90210, tv.tv_program.regular_cast, m.02t8pzz
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.0220tc8
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0wyc5nx
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.02t8d0c
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tdz
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0wybz18
Lori Loughlin, Shenae Grimes join '90210' spinoff, common.resource.annotations, m.09w708c
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.0220tdz
'90210' spin-off: Rob Estes joins cast, common.resource.annotations, m.09w72fs
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tdz
'90210' spinoff: We have a matriarch!, common.resource.annotations, m.09w70bt
m.09w72fs, common.webpage.resource, '90210' spin-off: Rob Estes joins cast
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.02t8gyb
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0k94m_1
Beverly Hills, 90210 - Season 3, tv.tv_series_season.episodes, The Child Is Father to the Man
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.02t926d
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210, tv.tv_program.regular_cast, m.02t94lh
Beverly Hills, 90210 - Season 4, tv.tv_series_season.episodes, Emily (a.k.a. The Pink Pearl)
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.02t926d
Here's what the new '90210' will look like, common.resource.annotations, m.09y05pc
Beverly Hills, 90210 - Season 4, tv.tv_series_season.episodes, Acting Out
m.09ycr9w, common.webpage.resource, '90210' alums: Sad, lonely, and single, what gives?
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.09rffbv
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tdz
Beverly Hills, 90210 - Season 5, tv.tv_series_season.episodes, The Dreams of Dylan McKay
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.04fgn00
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0220tc8
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tdl
A real 'Beverly Hills, 90210' spinoff (as opposed to 'Dancing With the Stars'), common.resource.annotations, m.09y01ps
Beverly Hills, 90210, tv.tv_program.regular_cast, m.02t926d
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0220tfq
Beverly Hills, 90210 - Season 6, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210, tv.tv_program.program_creator, Darren Star
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.04fgn00
Beverly Hills, 90210 - Season 7, tv.tv_series_season.regular_cast, m.0220tdz
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tf6
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tc8
'90210' recap: Fun with stalking!, common.resource.annotations, m.09ym6z8
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.0220tfg
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tdl
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0c6nwx3
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.02t94lh
m.0220tg2, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.02t8mh8
Beverly Hills, 90210 - Season 4, tv.tv_series_season.regular_cast, m.04fgn00
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.04fgn00
m.0c6nwx3, tv.regular_tv_appearance.seasons, Beverly Hills, 90210 - Season 9
m.0220tgk, tv.regular_tv_appearance.actor, Brian Austin Green
m.09w753y, common.webpage.resource, '90210' casting: There's an APB out on Joe E. Tata!
m.0k94m_9, tv.regular_tv_appearance.series, Beverly Hills, 90210
Beverly Hills, 90210 - Season 9, tv.tv_series_season.regular_cast, m.0wyb_dp
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tg2
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tfg
Beverly Hills, 90210 - Season 5, tv.tv_series_season.regular_cast, m.0220tdl
Beverly Hills, 90210, tv.tv_program.regular_cast, m.02t8d0c
m.09w6vvh, common.webpage.resource, Babe Alert! '90210' spinoff lands AnnaLynne McCord
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wybz18
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wyc5nx
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0k94m_1
m.0k94m_1, tv.regular_tv_appearance.series, Beverly Hills, 90210
m.0220tgk, tv.regular_tv_appearance.character, David Silver
Beverly Hills, 90210 - Season 8, tv.tv_series_season.regular_cast, m.0220tgk
Beverly Hills, 90210 - Season 2, tv.tv_series_season.regular_cast, m.02t8d0c
Beverly Hills, 90210 - Season 4, tv.tv_series_season.episodes, And Did It...My Way
Beverly Hills, 90210, tv.tv_program.regular_cast, m.0220tg2
Beverly Hills, 90210 - Season 10, tv.tv_series_season.regular_cast, m.0wyc1rh
Beverly Hills, 90210 - Season 3, tv.tv_series_season.regular_cast, m.0220tdz

Answer: David Silver