Malcolm is studying alone in his room late at night when he hears a loud noise downstairs. His heartbeat increases significantly and his breathing becomes shallow. He wonders if a burglar has entered the house and decides to investigate

When he gets downstairs he discovers his cat has knocked over a plant stand. His body begins to relax and return to normal. Which part of his nervous system is responsible for returning Malcolm to a normal state?
A) spinal cord
B) somatic nervous system
C) sympathetic nervous system
D) parasympathetic nervous system

Answer: D
Rationale: The parasympathetic nervous system helps maintain homeostatic balance in the presence of change, and following sympathetic arousal, it works to return the body to a baseline, nonemergency state.