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

[EX Q]: Who composed Air on the G String?
[EX A]: air on the g string

[EX Q]: What is the name of the co-founder of Apple Computers who died in October 2011?
[EX A]: apple inc.

[EX Q]: In which Shakespeare play do the characters Duke Frederick and Charles the Wrestler appear?
[EX A]:
charles