instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Who composed Air on the G String?
answer:
air on the g string


question:
'Arthur Clennam', 'Jeremiah Flintwinch', and 'Edward Sparkler' are all characters in which Dickens' novel?
answer:
arthur clennam


question:
In which European country is the Briksdal Glacier?
answer:

briksdalsbreen