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

Ornette Coleman, Louis Armstrong and Charles Mingus are associated with what style of music?
charles mingus

What was the title of the 2012 duet between Rihanna and Chris Brown?

chris brown