The right option is Autonomic nervous system
The autonomic nervous system is a part of the nervous system that unconsciously regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response and urination. The autonomic nervous system has two divisions which are the sympathetic and the parasympathetic nervous system. The sympathetic nervous system constricts blood vessels and enhances both the heart rate and blood pressure while the parasympathetic nervous system slows the heart rate, enhances intestinal and gland activity, and relaxes sphincter muscles.