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': 'Radical neck dissection involves removal of: \nSelect and explain. \nA. Spinal accessory nerve, B. External juglar vein, C. Tail of parotid, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cadical neck dissection involves removal of:\n\nI - V Lymph nodes\nSpinal accesory nerve\nInternal juglar vein\nSternocleidomastoid.', 'role': 'assistant'}]