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

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

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.