instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
What canal opened in Egypt?
answer:
egypt


question:
Who wrote the 1939 book The Big Sleep?
answer:
the big sleep


question:
The song 'White Christmas' first featured in which film starring Bing Crosby?
answer:

bing crosby