Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: Alexander the Great died in which ancient city?

Answer: alexander the great


Question: James Dearden wrote which book, made into a famous film directed by Adrian Lyne, in 1987?

Answer: adrian lyne


Question: Brimstone is an old word for which chemical element?

Answer:
brimstone