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': 'Diabetic gangrene is due to A/E \nSelect and explain. \nA. Vasospasm, B. Atherosclerosis, C. Peripheral neuritis, D. Increased sugar in blood', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]