instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Which of these was the title of Bobby Darin's first million selling single?
answer:
bobby darin


question:
Who directed the 2005 film 'Brokeback Mountain'?
answer:
brokeback mountain


question:
Who played King Arthur in the 1967 musical film Camelot?
answer:

king arthur