This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'Commonest endocrine tumor of pancreas \nSelect and explain. \nA. A cells, B. B cells, C. Delta cells, D. VIPoma', 'role': 'user'}, {'content': "Answer: B \nExplanation: Insulinomas- arising from B cells of pancreas- are the commonest endocrine pancreatic tumour(60%). Gastrinomas - arising from non-beta cells (G cells) of the pancreas- are the 2nd most common endocrine pancreatic tumour. Then comes Glucagonomas (arising from A cells) and VIPomas (arising from D2 cells of pancreas). Reference : page 709-10 SRB's manual of surgery 5th edition", 'role': 'assistant'}]