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: Medicine
[{'content': "Most common tumor of pancreas is - \nSelect and explain. \nA. Insulinoma, B. Gastrinoma, C. APUD's omas, D. VLPoma", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]