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': 'Two months after tonsillectomy the patient has referred pain to ear, cause is - \nSelect and explain. \nA. Temporomandibular joint dislocation, B. Injury to glossopharyngeal (9th cranial) nerve, C. Injury to vagus nerve, D. Infection of tonsillar bed', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]