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': 'CBD microliths are diagnosed by \nSelect and explain. \nA. ERCP, B. EUS, C. HIDA, D. CT', 'role': 'user'}, {'content': 'Answer: B \nExplanation: CBD stones IOC is MRCP\nMicro stones are detected by EUS.', 'role': 'assistant'}]