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
Surgical intervention in acute pancreatitis is indicated in all, EXCEPT: 
Select and explain. 
A. Infected necrosis, B. Infected collection, C. Impacted gallstone in ampulla, D. None of the above
D: None of the above
Answer: D: None of the above 
Explanation: Surgical intervention in acute pancreatitis is reserved for patients with infected collections or infected necrosis only, or to relieve an impacted gallstone in the ampulla if endoscopic or radiologic treatments are unavailable or unsuccessful. Ref: Schwaz's principle of surgery 9th edition, chapter 33.