This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
Most common pancreatic tumor in MEN-1 is - 
Select and explain. 
A. Gastrinoma, B. Insulinoma, C. Glucagonoma, D. Somatostatinoma
A: Gastrinoma
Answer: A: Gastrinoma 
Explanation: Enteropancreatic tumors in MEN 1 are * Gastrinoma(>50%) * Insulinoma(10-30%) * Nonfunctioning and PPoma(20-55%) * Glucagonoma(<3%) * VIPoma(<1%) Reference : page 2336 Harrison's Principles of Internal Medicine 19th edition