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: Pathology
Diabetic gangrene is caused by 
Select and explain. 
A. Vasospasm, B. Peripheral neuritis, C. Atherosclerosis, D. None of the above
C: Atherosclerosis
Answer: C: Atherosclerosis 
Explanation: None