The correct option is A Pepsin → Trypsin → Peptidase
The correct chronological order for the enzyme activity of the given enzymes taking part in protein digestion is pepsin → trypsin → peptidase. Protein digestion takes place in two different phases: in the stomach and in the small intestine. Two of the substances secreted by the stomach, HCl (hydrochloric acid) and pepsinogen, interact to create pepsin, an enzyme that plays a very important role in protein digestion. Pepsin is one of three principal protein-degrading, or proteolytic, enzymes in the digestive system, the other two being chymotrypsin and trypsin. Pepsin is an enzyme whose zymogen (pepsinogen) is released by the chief cells in the stomach and that degrades food proteins into peptides.