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': "Rigler's triad doesn't include \nSelect and explain. \nA. Pheumobilia, B. Ectopic stone, C. Cholangitis, D. Intestinal obstruction", 'role': 'user'}, {'content': "Answer: C \nExplanation: Rigler's triad is a combination of findings on an abdominal radiograph of people with gallstone ileus, a condition\xa0where a large gallstone causes bowel obstruction.it consists of \n(a) Small bowel obstruction,\n(b) a gallstone outside the gallbladder\n(c) air in the bile ducts(pneumobilia).", 'role': 'assistant'}]