The correct answer is: B. Ptylin
Ptyalin is an enzyme found in saliva that begins the process of breaking down starch into sugars. It is a salivary amylase, which is an enzyme that breaks down carbohydrates. Ptyalin is produced by the salivary glands and is found in the saliva. It is active in the mouth and begins the process of breaking down starch into sugars. The sugars are then absorbed by the body.
Renin is an enzyme that is produced by the kidneys. It is involved in the production of angiotensin II, which is a hormone that helps to regulate blood pressure. Tenin is an enzyme that is found in the stomach. It is involved in the breakdown of proteins. Resin is a sticky substance that is produced by plants. It is used to protect the plants from damage.
Ptyalin is the only enzyme listed that is found in saliva. Renin, tenin, and resin are not found in saliva.