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
Arnold nerve is a branch of: 
Select and explain. 
A. Vagus nerve, B. Hypoglossal nerve, C. Glossopharyngeal nerve, D. Trigeminal nerve
A: Vagus nerve
Answer: A: Vagus nerve 
Explanation: 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).