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': 'Which of the following endocrine tumors is most commonly seen in MEN I \nSelect and explain. \nA. Insulinoma, B. Gastrinoma, C. Glucagonoma, D. Somatostatinoma', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Gastrinoma", 'role': 'assistant'}]