Classify the relation of question with context to one of these categories: 1) award received, 2) based on, collection, 3) conflict, 4) constellation, 5) convicted of, 6) date of death, 7) director, 8) drafted by, 9) educated at, 10) medical condition, 11) military branch, 12) narrative location, 13) occupation, 14) original network, 15) parent company, 16) point in time, 17) production company, 18) residence, 19) series, 20) service entry, 21) sex or gender, 22) spouse, 23) standards body question.

Context : ``Peter's Daughter'' is the seventh episode of the sixth season of Family Guy and originally aired November 25, 2007. 
Question : To which series does Peter's Daughter belong?
series

Context : Lakmé is an opera in three acts by Léo Delibes to a French libretto by Edmond Gondinet and Philippe Gille. 
Question : The Lakmé is based upon what?
based on

Context : Burroughs began work on A Princess of Mars in the summer of 1911 when he was 35. 
Question : What series is the episode A Princess of Mars part of?

series