This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
The treatment of choice for an 8 mm retained common bile duct (CBD) stone is 
Select and explain. 
A. Laparoscopic CBD exploration, B. Percutaneous stone extraction, C. Endoscopic stone extraction, D. Extracorporeal shock wave lithotripsy
C: Endoscopic stone extraction
Answer: C: Endoscopic stone extraction 
Explanation: For CBD stones, endoscopic papillotomy is the preferred first technique with a sphincterotomy, removal of stones using Dormia basket or balloon catheter.ERCP can be used to remove retained CBD stones in 3 weeks of surgery. Reference: SRB&;s manual of surgery,5th edition, page no:652.