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

Who played 'Emma Peel' in the 1998 film 'The Avengers'?
the avengers

On which date do we celebrate 'Boxing Day'?
boxing day

Which American author wrote the novels 'Sophie's Choice' and 'The Confessions of Nat Turner'?

sophie's choice