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: Pathology
Most common site for gastrinoma - 
Select and explain. 
A. Duodenum, B. Pylorus, C. Antrum, D. Colon
A: Duodenum
Answer: A: Duodenum 
Explanation: Ans. is 'a' i.e., DuodenumUpto 50% gastrinoma are found in duodenum.