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

[EX Q]: What was the first Apollo mission to leave Earth orbit and orbit the moon, in 1968?
[EX A]: apollo

[EX Q]: The Bob Dylan songs 'Desolation Row', 'Tombstone Blues' and 'Like A Rolling Stone' featured on which album?
[EX A]: tombstone blues

[EX Q]: Which Belgian won the 2009 US Open Women's Tennis Singles Championship?
[EX A]:
us open