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: Pathology
[{'content': 'The most common site for carcinoma of the pancreas - \nSelect and explain. \nA. Head, B. Ampulla, C. Body, D. Tail', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pancreatic carcinoma \n\nPancreatic carcinoma is the most common malignant tumor of pancrease.\n\nRisk factors\n\nSmoking → Most consistent risk factor. \xa0\xa0\nChronic pancreatitis \xa0 \xa0\xa0\nObesity\nHigh fat, low fibre diet.\nDiabetes\n\nPathology\n\nPancreatic carcinoma are ductal adenocarcinomas.\nThe most common site is head of pancreas. The distribution is as follows.\n\nHead (70%)\nBody (20%)\nTail (10%)', 'role': 'assistant'}]