You are home alone one evening when you hear some noises coming from the kitchen. Your heart rate increases and your mouth becomes dry. This is BEST explained by the activation of your system.

sympathetic nervous.

Explanation:

The sympathetic nervous system is part of the autonomous nervous system drives the rapid involuntary response of the body in hazardous or stressful situations. It controls essential bodily functions including body temperature, sweating, heart rate, blood pressure, pupil dilation, and digestion without conscious control. As per the question, the increase in heart rate and mouth becoming dry are controlled by sympathetic nervous.