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

[EX Q]: Which 1970s musical film starred Angela Lansbury as a trainee witch?
[EX A]: angela lansbury

[EX Q]: In which Shakespeare play do the characters Ajax, Achilles and Ulysses appear?
[EX A]: achilles

[EX Q]: In 1947, a research physicist Chester Carlson set up which company to sell his invention, an office machine?
[EX A]:
chester carlson