TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: After Harold McMillan who was Britain's next Prime Minister?

SOLUTION: britain

PROBLEM: Chris Difford and Glenn Tilbrook founded which band in 1974?

SOLUTION: chris difford

PROBLEM: Which rock group was founded in Seattle in 1994 by David Grohl after the break-up of Nirvana?

SOLUTION:
nirvana