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': 'Which is not true of carbuncle - \nSelect and explain. \nA. Infective gangrene of subcutaneous tissue, B. Caused by staphylococcus, C. Diabetics are more prone, D. Caused by streptococcus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]