After cautiously walking home and arriving safely from her late-night class, selma notices that both her heart rate and breathing slow down. this automatic return to a normal state is due to the activity of her nervous system.

Parasympathetic nervous system (PNS)

The PNS in one part of the autonomic nervous system. The other part of the autonomic nervous system is the sympathetic nervous system.

The sympathetic nervous system is basically the body’s fight or flight response in face of threat or perceived threat. The symaptheic nervous system causes bodily responses such as fast heart rate, shallow and quick breathing, suppression of digestive system, etc.

The parasympathetic nervous system (PNS) on the other hand has the exact opposite effect on the body after a risky situation has passed(where the sympathetic  nervous system was activated). The PNS relaxes and provides the body with rest after arousal- heart rate slows down, breathing slows down, digestive functioning returns to normal.

Therefore, in Selma’s case after she was in a state of arousal from fear of arriving home safely, her parasympathetic nervous system got activated (slower breathing and heart rate) once she got home and was no longer in the dangerous situation. 

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.