Answer:
The best answer to the question: Parietal cells secrete:___, would be, C: Hydrocloric acid (HCI).
Step-by-step explanation:
Parietal cells are epithelial cells that can be found in the gastric glands both at the linings of both the fundus and cardia portions of the stomach. These cells are responsible in the process of digestion and absorption of nutrients, for the production of two chemical substances: intrinsic factor, necessary for the correct absorption of vitamin B12 later on in the ileum and also HCI, or hydrocloric acid. This acid will lower the pH of the stomach´s contents to enable correct and proper enzymatic work on proteins, most importantly. Its presence also stimulates the singaling by neurons to other organs of the GI tract to produce the necessary enzymes for proper digestion and absorption of the different nutrients.