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': 'Cystosarcoma phylloides is treated by - \nSelect and explain. \nA. Simple mastectomy, B. Radical mastectomy, C. Modified radical mastectomy, D. Antibiotic with conservative treatment', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]