What effect does extreme temperature and extreme ph have on enzyme activity?

it speeds up enzyme activity.
it slows down enzyme activity.
it stops enzyme activity.
it has no effect on enzyme activity.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

it is either c or d and i know for sure it is not a or b