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

[Q]: Who was Prime Minister of Australia at the outbreak of World War I?
[A]: australia

[Q]: The Battle of Poltava in 1709 was a victory by Peter the Great over which state?
[A]: battle of poltava

[Q]: Following which singer's death last year did the album 'Back To Black' top the UK charts for three weeks?
[A]:
back to black