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: ENT
[{'content': 'In malignant lesion in pyriform fossa pain is referred to ear via \nSelect and explain. \nA. Glossopharyngeal nerve, B. Vagus nerve, C. Brachial plexus, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]