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 county town of Derbyshire?

Answer: derbyshire


Question: Written by Edgar Allen Poe and published in 1845, what poem repeats the famous line `nevermore`?

Answer: edgar allan poe


Question: The Tropic of Capricorn is feature on which planet?

Answer:
capricorn