Proton Pump Inhibitors (or PPIs) are some of the widely used drugs in the world and are prescribed for chronic heartburn/acid reflux. They work by inhibiting the movement of H⁺ ions across the membrane into the gastric juice, thereby lowering the concentration of HCl. As described, which cell of the gastric glands would you expect PPIs to affect?

• A. Chief cells.
• B. Enteroendocrine cells.
• C. Mucous neck cells.
• D. Parietal cells.