Answer:
(B). H⁺/K⁺ ATPase.
Step-by-step explanation:
H⁺/K⁺ ATPase (or hydrogen-potassium pump) is a proton pump, present in parietal cells of stomach. The main function of hydrogen-potassium pump is to acidify the contents of stomach and to activate pepsin (a digestive enzyme).
It helps in gastric acid formation releasing hydrogen ions to the lumen with exchange of potassium ions.
Gastric acid reflux represents a condition, in which stomach acid comes up to the esophagus from stomach. Hence, one way to treat gastric acid reflux is to inhibit H⁺/K⁺ ATPase that would decrease synthesis of gastric acid in stomach.
Thus, the correct answer is option (B).