This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'Arnold nerve is a branch of: \nSelect and explain. \nA. Vagus nerve, B. Hypoglossal nerve, C. Glossopharyngeal nerve, D. Trigeminal nerve', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Vagus nerveRef: Dhingra's ENT 6th ed/4* Arnold's nerve is the auricular branch (also known as the mastoid branch) of the vagus nerve (CN X).* It originates from the superior ganglion of the vagus nerve* Arnold's nerve along with facial nerve innervates concha of auricle and the external acoustic meatus (posterior and inferior wall).", 'role': 'assistant'}]