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

[Q]: Who plays Isobel Crawley in the UK television series 'Downton Abbey'?
[A]: downton abbey

[Q]: Who is the BBC's political editor?
[A]: bbc

[Q]: Who directed the 1985 film Back To The Future?
[A]:
back to the future