instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
In which war was the Battle of Bunker Hill?
answer:
battle of bunker hill


question:
What's the name of Doctor Who's home planet ?
answer:
doctor who


question:
In which US State are the cities of Chattanooga, Lynchburg and Shelbyville?
answer:

lynchburg