The process of digesting your last snack or meal or the unconscious regulation of your breathing are all primarily rooted in the nervous system. secondary somatic autonomic limbic primary

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.

Autonomic limbic somatic secondary

Limbic system is known to be an area of the brain that is involved in memory and emotion.They interact with autonomic nervous system and reticular activating system to assist the body in process emotions. Thus, the structures of the limbic system includes amygdala, mammillary bodies, the hippocampus and cingulate gyrus.

b is the correct answer