TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Who played the character Gene Hunt in the UK TV series 'Life on Mars' and 'Ashes to Ashes'?

SOLUTION: life on mars

PROBLEM: Who has taken over the TV role of Doctor Who, from actor David Tennant?

SOLUTION: doctor who

PROBLEM: Which England cricket captain was born in Madras in 1968?

SOLUTION:
cricket