This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
Tumor commonly seen in the area marked below 
Select and explain. 
A. Insulinoma, B. Gastrinoma, C. Non-functional tumours, D. VIPoma
B: Gastrinoma
Answer: B: Gastrinoma 
Explanation: Most sporadic gastrinomas are located in the first and second pa of the duodenum. The anatomical area comprising the head of the pancreas, the superior and descending poion of the duodenum and the relevant lymph nodes has been called the 'gastrinoma triangle' because it harbours the vast majority of these tumoursRef: Bailey and Love 27e pg: 851