The correct option is C Conversion of pepsinogen to pepsin
In the presence of peptides in the stomach, gastrin hormone is released into the bloodstream. This hormone stimulates the gastric glands to produce gastric juice. Gastric juice is an acid juice (pH 1 - 3). HCl (Hydrochloric Acid) keeps the stomach pH acidic. As HCl is a strong acid, it will kill most of the bacteria present in the food. The other main function is to convert pepsinogen into pepsin.