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: who played heath barkley? 
Knowledge Triplets: The Big Valley, film.film.starring, m.0h8mhz5
Film character, freebase.type_hints.included_types, Fictional Character
Travis Fimmel, film.actor.film, m.0h8mhz5
m.04d576s, tv.regular_tv_appearance.actor, Lee Majors
Character, type.property.expected_type, Film character
Heath Barkley, tv.tv_character.appeared_in_tv_program, m.04d576s
Character, owl#inverseOf, Portrayed in films
Film character, type.type.expected_by, Killed by
Character, type.property.reverse_property, Portrayed in films
Film character, type.type.expected_by, Character using Wham-O product
Film character, common.topic.article, m.02_96_z
Heath Barkley, common.topic.notable_types, Film character
m.04d576s, tv.regular_tv_appearance.series, The Big Valley
Heath Barkley, film.film_character.portrayed_in_films, m.0h8mhz5
The Big Valley, tv.tv_program.regular_cast, m.04d576s
m.0h8mhz5, film.performance.actor, Travis Fimmel
Film character, freebase.type_profile.kind, Portrayal
Lee Majors, tv.tv_actor.starring_roles, m.04d576s
m.0h8mhz5, film.performance.film, The Big Valley
Heath Barkley, film.film_character.portrayed_in_films, m.0h8mhz5
Film character, freebase.type_profile.strict_included_types, Fictional Character
Film character, type.type.properties, Portrayed in films
Film character, type.type.properties, Portrayed in films (dubbed)
Fictional Character, freebase.type_profile.published, Published
Fictional Character, freebase.type_hints.included_types, Topic
Film character, type.type.expected_by, Other conquests
Film character, type.type.domain, Film
m.0h8mhz5, film.performance.character, Heath Barkley
Character, rdf-schema#range, Film character
Heath Barkley, common.topic.article, m.0h8mjl5
m.0h8mhz5, film.performance.actor, Travis Fimmel
Film character, freebase.type_profile.published, Published
Film character, type.type.expected_by, Character
Fictional Character, freebase.type_profile.kind, Portrayal
Film character, freebase.type_hints.included_types, Topic
Film character, freebase.type_profile.strict_included_types, Topic
Heath Barkley, common.topic.notable_for, g.12594n4k6
Film character, freebase.type_profile.kind, Annotation
m.04d576s, tv.regular_tv_appearance.character, Heath Barkley
Fictional Character, freebase.type_profile.strict_included_types, Topic
m.0h8mjl5, common.document.content, m.0h8mjkx

Answer: Travis Fimmel