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 treatment of gall stone ileus is \nSelect and explain. \nA. Cholecystectomy alone, B. Removal of obstruction, C. Cholecystectomy, closure of fistula and removal of stone by enterotomy, D. Cholecystectomy with closure of fistula', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]