TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Name Shakespeare play Ariel, Miranda and Prospero appear?

SOLUTION: ariel

PROBLEM: Christopher Eccleston, Kerry Fox and Ewan McGregor played flatmates in which 1994 film?

SOLUTION: christopher eccleston

PROBLEM: David Lean directed the 1945 film 'Brief Encounter', but who composed the incidental music and also produced the film?

SOLUTION:
brief encounter