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

[Q]: Who is the only British Prime Minister to serve under 3 monarchs?
[A]: prime minister of the united kingdom


[Q]: What type of creature is an argali?
[A]: argali


[Q]: What was Casanova's occupation at the time of is death?
[A]:
giacomo casanova