This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
[{'content': 'Most common and most malignant neuroendocrine tumour of pancreas? \nSelect and explain. \nA. Gastrinoma, B. Glucagonoma, C. Insulinoma, D. VIPoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) GastrinomaRef: Sabiston 20th edition Page 954* MC functioning endocrine neoplasm of pancreas - insulinoma* MC endocrine neoplasm in MEN - 1 Syndrome - Gastrinoma* MC and most malignant endocrine neoplasm - gastrinoma* MC neuroendocrine tumor - Nonfunctioning tumors', 'role': 'assistant'}]