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

[EX Q]: Which Best Picture nominated movie tells the story of US soldier, 'Chris' Kyle?
[EX A]: chris kyle

[EX Q]: Name Shakespeare play Ariel, Miranda and Prospero appear?
[EX A]: ariel

[EX Q]: What song gave Black Sabbath their highest charting hit?
[EX A]:
black sabbath