It would be the respiratory system
Answer:
A) parietal cells
Explanation:
Parietal cells are the epithelial cells of the stomach that have the function to secrete hydrochloric acid (HCl) and intrinsic factor. Parietal cells contain canaliculi – secretory network for the secretion of HCl via active transport.
Parietal cells are regulated via several factors such as acetylcholine, gastrin and histamine. So, if histamine receptors are blocked via antacid drugs , the secretion of the acid will be reduced.
We can rule out small fish and grasses. My guess is that zooplankton get their energy from phytoplankton, because phytoplankton use photosynthesis to get their energy.
