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

[EX Q]: Which SF author wrote The Day it Rained Forever?
[EX A]: the day it rained forever

[EX Q]: In which bay is Alcatraz?
[EX A]: alcatraz island

[EX Q]: What was the name of the series of religiously sanctioned military campaigns between 1095 and 1291 waged by much of Latin Christian Europe to restore Christian control of the Holy Land?
[EX A]:
christendom