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: Medicine
Most common presenting symptom of Zollinger -Ellison syndrome is: 
Select and explain. 
A. Diarrhea, B. Pain, C. Esophageal symptoms, D. Flushing
B: Pain
Answer: B: Pain 
Explanation: Zollinger -Ellison syndrome symptoms and their frequencies Pain (79-100%), diarrhea (30-75%), esophageal symptoms (31-56%) and flushing is not a feature of this disease. Ref: Harrisons principles of internal medicine, 18th edition, Page: 3057