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': 'Commonest cause for bile duct infection is which of the following condition ? \nSelect and explain. \nA. Clonorchis, B. Common Bile Duct stone, C. Periampullary Ca, D. Ca head of pancreas', 'role': 'user'}, {'content': "Answer: B \nExplanation: Charcoat's cholangitis triad, a feature of bile duct infection, consists of pain, fever and jaundice.", 'role': 'assistant'}]