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

[EX Q]: Christian Grey is a character in what recent book trilogy?
[EX A]: christian grey

[EX Q]: In 2011, Christian Bale won a Best Supporting Actor Oscar for his role as an assistant to his half-brother in which boxing related film?
[EX A]: christian bale

[EX Q]: Who composed the opera Aida?
[EX A]:
aida