This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Zollinger Ellision Syndrome, Subject name: Medicine
Not a feature of ZES? 
Select and explain. 
A. Diarrhea non-responsive to fasting, B. Epigastric pain, C. Large gastric ulcer, D. Secretin study is the investigation of choice
C: Large gastric ulcer
Answer: C: Large gastric ulcer 
Explanation: Feature of ZES. Diarrhea non- responsive to fasting (secretory diarrhea) Epigastric pain 2nd pa of Duodenum, Multiple duodenum ulcer (Not present in stomach) Secretin study in the IOC - BAO/MAO = 0.6