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: Surgery
[{'content': 'Structures preserved in Radical Neck Dissection is : \nSelect and explain. \nA. Vagus nerve, B. Submandibular gland, C. Sternocleidomastoid, D. Internal Jugular Vein', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Vagus nerve", 'role': 'assistant'}]