This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Kidney Disease & Diabetic Nephropathy, Subject name: Medicine
Acute auto-graft rejection occurs within? 
Select and explain. 
A. Few hours, B. < 1 month, C. < 6 months, D. 6-12 months
C: < 6 months
Answer: C: < 6 months 
Explanation: Hypersensitivity reaction Time 1. Hyperacute II Minutes 2. Acute IV <6 months 3. Chronic IV >6 months