instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
The Battle of Antietam was fought during which war?
answer:
battle of antietam


question:
The most northerly part of mainland Australia is in which state?
answer:
australia


question:
Bella Wilfer is a character in which of Charles Dickens' books?
answer:

charles dickens