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.

[EX Q]: Why did the united states pursue a policy of containment?
[EX A]: prevent the spread of communism after the end of World War II

[EX Q]: Who sang the facts of life theme song?
[EX A]: Gloria Loring

[EX Q]: By what term do we call the level of output generated by a given volume of inputs?
[EX A]:
Productivity