instruction:
In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
question:
Who's the best selling artist of all time?
answer:
The Beatles


question:
Who has played for the most premiership clubs?
answer:
Andy Cole and Peter Crouch


question:
Fracking is used primarily to extract oil and gas from?
answer:

hard rock