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
[{'content': 'The procedure of choice for elective removal of CBD stones for most patients is - \nSelect and explain. \nA. Open choledocholithotomy, B. Endoscopic papillotomy, C. Laparoscopic choledocholithotomy, D. Percutaneous choledocholithotomy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: • ERCP: Diagnostic and therapeutic test of choice for patients with suspected CBD stones\n• CBD stones are classified by point of origin\n• Found in 6–12% of patients with GB stones\n• Retained stones discovered within 2 years of cholecystectomy\n• Recurrent stones detected >2 years following cholecystectomy\n• ERCP: Diagnostic and therapeutic test of choice for patients with suspected CBD stones.\nTreatment\n• Treatment options are ERCP, laparoscopic or open CBD Exploration.', 'role': 'assistant'}]