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': 'Biliary stricture developing after Laparoscopic cholecystectomy usually occurs at which pa of the common bile duct? \nSelect and explain. \nA. Upper, B. Middle, C. Lower, D. All sites with equal frequency', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e. Upper Most common duct injuries occur when the CBD or CHD or hepatic duct is mistaken to be the cystic duct and ligated and/or divided. Most common site involved is upper CBD.", 'role': 'assistant'}]