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': 'Reverse 8 sign of frost berg seen in \nSelect and explain. \nA. Duodenal atresia, B. Ampullary carcinoma, C. CA head pancreas, D. Jeyunal atresia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Reverse 3 sign of frost berg seen in ampullary carcinoma of pancreas.', 'role': 'assistant'}]