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

Ex Input:
'Arthur Clennam', 'Jeremiah Flintwinch', and 'Edward Sparkler' are all characters in which Dickens' novel?

Ex Output:
arthur clennam


Ex Input:
What is the SI unit of capacitance?

Ex Output:
capacitance


Ex Input:
Ambigu was an early form of what card game?

Ex Output:

card game