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: Medicine
[{'content': 'Not a risk for cholangio carcinoma - \nSelect and explain. \nA. Hepatolithiasis, B. Hepatitis C, C. Clonorchi sinensis, D. Choledocholithiasis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: </p> Davidson&;s principles and practice of medicine 22nd edition. *The tumour is associated with gallsgallstones,primary and secondary cholangitis,caroli&;s disease and choledochalcyst,chronic liver fluke infection (clonorchis sinensis) is the major risk factor for development for CCA.</p>', 'role': 'assistant'}]