Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Q: Which is the only Avril Lavigne song to have reached No.1 in the US Billboard Chart?

A: avril lavigne
****
Q: Created by Alex Raymond, this futuristic character first appeared in 1934. Who is he?

A: alex raymond
****
Q: Bismark is the capital of which US state?

A:
bismarck
****