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': 'A patient was asked to protrude his tongue and salt was placed on the anterior 2/3rd of the tongue. This \nprocedure is used for testing which nerve? \nSelect and explain. \nA. V, B. VII, C. IX, D. X', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The sensory nerve ﬁbers from the taste buds on the anterior two-thirds of the tongue travel in the\xa0chorda tympani branch of the facial nerve, and 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'}]