TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: What was the first Apollo mission to leave Earth orbit and orbit the moon, in 1968?

SOLUTION: apollo

PROBLEM: Played by Dirk Benedict in the series and Bradley Cooper in the movie, by what nickname was Templeton Peck known on The A-Team?

SOLUTION: the a-team

PROBLEM: Which planet has one moon called Charon?

SOLUTION:
charon