Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: Which instrument was Benny Goodman famous for playing?

Answer: benny goodman


Question: In May 1940, who became British Prime Minister after the resignation of Neville Chamberlain?

Answer: prime minister of the united kingdom


Question: Name the British Prime Minister at the outbreak of WW1?

Answer:
prime minister of the united kingdom