The nervous system provides involuntary regulation of smooth muscle, cardiac muscle, and glandular activity.

The autonomic nervous system provides involuntary regulation of smooth muscle, cardiac muscle, and glandular activity. It is part of the nervous system that works automatically and regulates some of the body processes. The autonomic nervous system is responsible for control of the following processes: breathing, blood pressure, digestion, metabolism, body temperature, production of body fluids,...

C- a hypothesis or d- an observation

The answer is d i think