instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
What is the Army equivalent to a Group Captain in the R.A.F.?
answer:
british army


question:
Which of these was the title of Bobby Darin's first million selling single?
answer:
bobby darin


question:
Who wrote the novel  The Picture of Dorian Grey?
answer:

the picture of dorian gray