This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharynx, larynx and trachea and cranial nerves 3,4,6, Subject name: Anatomy
[{'content': 'A 38-year-old man has had thyroid surgery to remove his papillary carcinoma. The external laryngeal nerve that accompanies the superior thyroid aery is damaged during the surgery.This injury could result in a severe impairment of function of which of the following \nSelect and explain. \nA. Relaxing the vocal cords, B. Rotating the arytenoid cailages, C. Tensing the vocal cords, D. Widening the rima glottidis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The External laryngeal nerve innervates the cricothyroid muscle (major tensor), which tenses the vocal cord. Hence damage to this nerve will lead to inability to tense the vocal cords.', 'role': 'assistant'}]