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

[Q]: Lexus is the luxury vehicle division of what car maker?
[A]: lexus

[Q]: James Dearden wrote which book, made into a famous film directed by Adrian Lyne, in 1987?
[A]: adrian lyne

[Q]: Constantine XI Palaiologos was the last ruler of which empire?
[A]:
constantine xi palaiologos