instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
The most northerly part of mainland Australia is in which state?
answer:
australia

question:
What horse won the 2009 Grand National?
answer:
2009 grand national

question:
At which Grand prix circuit was Ayrton Senna killed in 1994?
answer:
ayrton senna