This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
Most common and most malignant neuroendocrine tumour of pancreas? 
Select and explain. 
A. Gastrinoma, B. Glucagonoma, C. Insulinoma, D. VIPoma
A: Gastrinoma
Answer: A: Gastrinoma 
Explanation: Ans. (a) GastrinomaRef: Sabiston 20th edition Page 954* MC functioning endocrine neoplasm of pancreas - insulinoma* MC endocrine neoplasm in MEN - 1 Syndrome - Gastrinoma* MC and most malignant endocrine neoplasm - gastrinoma* MC neuroendocrine tumor - Nonfunctioning tumors