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': 'M/C site of cholangio CA: \nSelect and explain. \nA. ntrahepatic, B. Distal biliary tract, C. Hilum, D. Multifocal', 'role': 'user'}, {'content': "Answer: C \nExplanation: Hilum Risk factor for cholangio carcinoma * Primary sclerosing cholangitis * Choledochal cyst * Ulcerative colitis * Clonorchis sinensis injection * Chronic typhoid carries 2/3 of cholangio carcinoma are located at hepatic duct bifurcation here they are called as KLATSKIN's tumoursQ M/C type is adeno carcinomaQ *Painless jaundice is the most common presentation", 'role': 'assistant'}]