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: Anatomy
[{'content': 'The procedure of choice for elective removal of CBD stones for most patients is \nSelect and explain. \nA. Open choledocholithotomy, B. Laparoscopic choledocholithotomy, C. Endoscopic choledocholithotomy, D. Percutaneous choledocholithotomy', 'role': 'user'}, {'content': "Answer: A \nExplanation: Elective definitive treatment Cholecystectomy with choledochotomy and CBD exploration T-tube is left in place for cholangiography and removal of any retained stone T-tube cholangiogram is done on 7th - 10th day Post-operatively Remove the T-tube if cholangiogram is normal If residual stone is discovered on the postoperative cholangiogram, T-tube should be left in place for 4-6 weeks for the tract to mature The stones are removed percutaneously through the matured tract by Burhenne's technique Ref: Sabiston 20th edition Pgno : 1511", 'role': 'assistant'}]