This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
[{'content': 'Most common site of cholangiocarcinoma? \nSelect and explain. \nA. Distal biliary duct, B. Hilum, C. Intrahepatic duct, D. Multifocal', 'role': 'user'}, {'content': "Answer: B \nExplanation: Most common site for cholangiocarcinoma is perihilar region(65%).Distal pa of duct constitutes 25% &Intrahepatic pa constitutes around 10%. Reference:SRB's manual of surgery,5th edition,page no:661.", 'role': 'assistant'}]