Which among the following is a protein digesting enzyme ?

Pepsin 

The correct answer is Option (3) –Pepsin

The digestion in stomach is taken care of by the gastric glands present in the wall of the stomach. These release hydrochloric acid, a protein digesting enzyme called pepsin, and mucus.  The hydrochloric acid creates an acidic medium which facilitates the action of the enzyme pepsin. 

Pepsin is produced in the stomach and is one of the main digestive enzymes, which helps in digestion of the proteins in food.