This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal tract, Subject name: Pharmacology
Esomeprazole acts by inhibiting: 
Select and explain. 
A. H+K+ ATPase pump, B. H+Na+ ATPase pump, C. H+ pump, D. Any of the above
A: H+K+ ATPase pump
Answer: A: H+K+ ATPase pump 
Explanation: Esmoprosol is an example of proton pumb inhibitor ESSENTIALS OF MEDICAL PHARMACOLOGY SEVENTH EDITION KD TRIPATHI PG NO.653