This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'Which nerve is being tested by putting salt on the tip of the tongue? \nSelect and explain. \nA. V, B. IX, C. XII, D. VII', 'role': 'user'}, {'content': 'Answer: D \nExplanation: KEY CONCEPT:\nThe sensory nerve ﬁbers from the taste buds on the anterior two-thirds of the tongue travel in the\xa0 chorda tympani branch of the facial nerve\xa0and those from the posterior third of the tongue reach the\xa0 brainstem via the glossopharyngeal nerve. The ﬁbers from areas other than the tongue (eg, pharynx)\xa0 reach the brain stem via the vagus nerve.', 'role': 'assistant'}]