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
Which of following is a proton pump inhibitor ? 
Select and explain. 
A. Magnesium carbonate, B. Ranitidine, C. Omeprazole, D. Sucralfate
C: Omeprazole
Answer: C: Omeprazole 
Explanation: Ans. is 'c' i.e., Omeprazole