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: Pharmacology
Drug of choice for Zollinger Ellison syndrome: 
Select and explain. 
A. Proton pump inhibitor, B. Antacids, C. Antithistminics, D. H2 blockers
A: Proton pump inhibitor
Answer: A: Proton pump inhibitor 
Explanation: Proton pump inhibitor