DIGESTIVE SYSTEM - GLANDS-17 : HORMONE A-CELLS OF PANCREATIC ISLET: a. glucagon b. VIP -hormone D C. sematostatin D d. insulin e. PP-hormone

The correct answer is a. glucagon.<br /><br />Glucagon is a hormone produced by the alpha cells of the pancreatic islets. It plays a crucial role in regulating blood glucose levels by promoting the breakdown of glycogen into glucose in the liver. This process is known as glycogenolysis. When blood glucose levels are low, glucagon is released into the bloodstream, stimulating the liver to release glucose into the bloodstream to maintain normal blood sugar levels.