Answer:
The correct answer is: c) the heart rate slowed and eventually stopped.
Explanation:
The vagus nerve (X) is a cranial nerve with the function to parasympathetically <u>innervate the heart, the lungs and the digestive tract. </u>
As a part of the Autonomic Nervous System (ANS), the vagus nerve regulates things such as heart rate and gastrointestinal peristalsis (things we cannot control).
Given that it is a component of the parasympathetic division of the ANS, it stimulates the organs when the individual is performing normal activities like <u>resting and feeding</u> (unlike the sympathetic division, responsible for the fight-or-flight response). For this specific reason, the vagus nerve slows the heart rate, so if it were to be stimulated in a frog, it would produce the same thing and ultimately lead to its heart stopping.