The part of the nervous system that quiets the body after arousal and maintain vital functions (like breathing) at moderate levels is the branch. science forum

The answer is the parasympathetic system. It is referred to as the system that invokes ‘feed and rest’ and ‘rest and digest’ during resting. This is invoked epically after a spike in activity such and sexual arousal, defecation, salivation, lacrimation, and digestion. It complements the sympathetic system in achieving homeostasis.

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.