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
Which of the following endocrine tumors is most commonly seen in MEN I 
Select and explain. 
A. Insulinoma, B. Gastrinoma, C. Glucagonoma, D. Somatostatinoma
B: Gastrinoma
Answer: B: Gastrinoma 
Explanation: Ans. is 'b' i.e., Gastrinoma