instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Where is Charles Darwin buried?
answer:
charles darwin


question:
Which Noble prize-winning novelist is best known for 'And Quiet Flows the Don?
answer:
and quiet flows the don


question:
Which Doctor Who actor did David Bradley play in the recent TV drama An Adventure In Space and Time ?
answer:

doctor who