instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
The Bob Dylan songs 'Desolation Row', 'Tombstone Blues' and 'Like A Rolling Stone' featured on which album?
answer:
tombstone blues


question:
Which American city has baseball-playing 'Dodgers'?
answer:
los angeles dodgers


question:
In Arthurian legend, what is the name of the enchantress who is Arthur's half sister?
answer:

king arthur