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:
How are point sources of pollution regulated by the cwa?
answer:
requires dischargers to obtain a National Pollutant Discharge Elimination System (NPDES) permit


question:
In the united kingdom who picks the prime minister?
answer:
the reigning monarch appoints


question:
Journal of optics a pure and applied optics abbreviation?
answer:

J. Opt.