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
Omeprazole is a 
Select and explain. 
A. Antihistamine, B. Proton pump inhibitor, C. Ulcer protective, D. Ulcer healing drug
B: Proton pump inhibitor
Answer: B: Proton pump inhibitor 
Explanation: None