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

Example Input: Which evolutionary biologist wrote The Ancestor's Tale in 2004?
Example Output: the ancestor's tale

Example Input: Established in 1919, which is the world's oldest surviving airline?
Example Output: airline

Example Input: Which English football club play their home games at Craven Cottage?
Example Output:
craven cottage