Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.

[Q]: Which tree belongs to the genus Betula?
[A]: birch


[Q]: Who hit No.1 with Hollaback Girl in 2005?
[A]: gwen stefani


[Q]: 'Forty Years On' is the title of the first West End play by which British playwright?
[A]:
alan bennett