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

[EX Q]: Thereze Bazar and David van Day were better known as which duo?
[EX A]: david van day

[EX Q]: Which chemical element is named after the Latin for Copenhagen where it was discovered?
[EX A]: copenhagen

[EX Q]: Which group of Marvel superheroes fought Doctor Doom?
[EX A]:
doctor doom