Activation of the parasympathetic nervous system primarily leads to which of the following physiological effects?

The correct answer to the question "Activation of the parasympathetic nervous system primarily leads to which of the following physiological effects?" is Option C: Contraction of the detrusor muscle and pupillary constriction.

The other options — A) Increased heart rate and bronchodilation, B) Pupil dilation and decreased peristalsis, D) Peripheral vasoconstriction and glycogenolysis — are incorrect for this USMLE Exam Prep question. As explained above: The parasympathetic nervous system promotes 'rest and digest' functions, including contraction of the detrusor muscle for urination and pupillary constriction (miosis).