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

[EX Q]: In 2013 Yahoo purchased which pictures and video microblogging website business that was founded in 2007 in New York City by David Karp?
[EX A]: yahoo!

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

[EX Q]: Mario Batali, Cat Cora, Bobby Flay, Masaharu Morimoto and Micael Symon compete on what show?
[EX A]:
mario batali