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

[EX Q]: Although it was headquartered at Oak Ridge, TN, and the University of Chicago, what was the name of the WWII project that created the atomic bomb?
[EX A]: nuclear weapon

[EX Q]: With which song did Swedish pop group Abba win the 1974 Eurovision Song Contest?
[EX A]: abba

[EX Q]: Where is Charles Darwin buried?
[EX A]:
charles darwin