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

[EX Q]: Who composed 'Belshazzar's Feast' cantata?
[EX A]: belshazzar's feast

[EX Q]: Basil Rathbone made 14 Sherlock Holmes films. Who played the part of Dr Watson?
[EX A]: watson

[EX Q]: Who wrote The Communist Manifesto (1848) and Das Kapital (1867)?
[EX A]:
the communist manifesto