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': 'In pylorus, Pancreatoduodenectomy preserving following is not resected \nSelect and explain. \nA. Pyloric antrum, B. CBD, C. Duodenum, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. Pyloric antrumThe standard resection for a tumour of the pancreatic head or the ampulla is a pylorus-preserving pancreatoduodenectomy (PPPD).', 'role': 'assistant'}]