Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

[EX Q]: Christopher Eccleston, Kerry Fox and Ewan McGregor played flatmates in which 1994 film?
[EX A]: christopher eccleston

[EX Q]: Who played the character Gene Hunt in the UK TV series 'Life on Mars' and 'Ashes to Ashes'?
[EX A]: life on mars

[EX Q]: Which actor, (the eighth Doctor Who) played the role just once in a 1996 TV movie?
[EX A]:
eighth doctor