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': 'In Radical mastectomy, which is spared- \nSelect and explain. \nA. Pectorialis major, B. Pectoralis minor, C. Axillary lymph nodes, D. Supraclavicular lymph nodes', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]