This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastro-Intestinal Tract, Subject name: Pharmacology
Drug of choice for Zollinger-Ellison syndrome is:- 
Select and explain. 
A. Cimetidine, B. Omeprazole, C. Misoprostol, D. Aluminium hydroxide
B: Omeprazole
Answer: B: Omeprazole 
Explanation: Proton pump inhibitors are the drugs of choice for peptic ulcer disease (PUD) due to any etiology (even NSAID induced). These are also the agents of choice for gastroesophageal reflux disease (GERD) and Zollinger Ellison Syndrome (ZES). Zollinger Ellison syndrome: It is a Pancreatic or duodenal gastrinoma which leads to secretion of large amounts of gastric acid causing severe ulcers and hyperchlorhydria. PPI are better than H2 blockers in this condition.