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

[EX Q]: What's the name of Doctor Who's home planet ?
[EX A]: doctor who

[EX Q]: Which singer/songwriter, who began releasing hit singles in 1958, has had 3 albums (The Definitive Collection, Waking Up Is Hard to Do & The Music of My Life) on Billboard's Top 200 Albums chart between 2007 & 2010?
[EX A]: the definitive collection

[EX Q]: Which 2004 film, directed by Mike Nicholls and starring Clive Owen, Julia Roberts, Jude Law and Natalie Portman concerns two obsessive couples whose intimacy pushes them further apart?
[EX A]:
julia roberts