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

[EX Q]: Where is David Cameron's Oxfordshire constituency?
[EX A]: david cameron

[EX Q]: Kronos (or Cronus) was the Greek equivalent of which Roman god?
[EX A]: cronus

[EX Q]: Who played the role of Caligula in the 1976 UK tv series 'I, Claudius'?
[EX A]:
caligula