"Disruptive selection" is the one mechanism among the choices given in the question that <span>brought this change in gene frequencies. The correct option among all the options that are given in the question is the fourth option or option "D". I hope that the answer has actually come to your help.</span>
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.