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: Medicine
All are risk factors for the development of surgery associated chronic kidney disease, EXCEPT: 
Select and explain. 
A. Older age, B. CCF, C. Emergency procedures, D. Spinal anaesthesia
D: Spinal anaesthesia
Answer: D: Spinal anaesthesia 
Explanation: Common risk factors for postoperative AKI include 1. Underlying chronic kidney disease, 2. Older age, 3. Diabetes mellitus, 4. Congestive hea failure 5. Emergency procedures. Cardiopulmonary bypass is a hemodynamic state characterized by nonpulsatile flow and exposure of the circulation to extracorporeal circuits. Longer duration of cardiopulmonary bypass is a risk factor for AKI. Ref: Harrison-E-18, P-2296.