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

[Q]: What horse won the 2009 Grand National?
[A]: 2009 grand national


[Q]: Which musical has the songs 'Another Suitcase In Another Hall' and 'Oh What A Circus'?
[A]: another suitcase in another hall


[Q]: Whose famous books include The Descent of Man, and Selection in Relation to Sex, The Expression of Emotions in Man and Animals,  The Power of Movement in Plants and The Formation of Vegetable Mould Through the Action of Worms?
[A]:
the power of movement in plants