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

Ex Input:
Aaron Copeland wrote a ballet about which American folk hero?

Ex Output:
aaron copeland

Ex Input:
To which country do the Chatham Islands belong?

Ex Output:
chatham islands

Ex Input:
Whose tale in Chaucer's The Canterbury Tales tells of a knight sent away by his queen to discover what women want above all else?

Ex Output:
the canterbury tales