TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM:  'The Dream of Gerontius' is the 1900 work of which English composer?

SOLUTION: the dream of gerontius

PROBLEM: Which 1970s musical film starred Angela Lansbury as a trainee witch?

SOLUTION: angela lansbury

PROBLEM: In western astrology, to which element do Cancer, Scorpio and Pisces belong?

SOLUTION:
pisces