The correct answer is: A. salivary glands.
Ptyalin is an enzyme that breaks down starch into maltose. It is produced in the salivary glands and is found in saliva. Ptyalin is active in the mouth and begins the process of digestion of carbohydrates.
The pituitary glands are located in the brain and produce hormones that control many body functions, including growth, reproduction, and metabolism. The thyroid glands are located in the neck and produce hormones that regulate metabolism, growth, and development. The pancreas is a gland located in the abdomen that produces digestive enzymes and hormones that regulate blood sugar levels.
Ptyalin is not produced in the pituitary glands, thyroid glands, or pancreas. It is produced in the salivary glands.