This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brainstem, cerebellum and ventricles, Subject name: Anatomy
The efferent limb of the gag reflex is? 
Select and explain. 
A. Facial nerve, B. Glossopharyngeal nerve, C. Trigeminal nerve, D. Vagal nerve
D: Vagal nerve
Answer: D: Vagal nerve 
Explanation: The gag reflex involves a brisk and brief elevation of the soft palate and bilateral contraction of pharyngeal muscles evoked by touching the posterior pharyngeal wall The vagus nerve (CN X) provides the efferent limb of the gag reflex (muscles of the soft palate). The glossopharyngeal nerve provides the afferent limb of the gag reflex.