Hormones

Step 1: Understanding glycogenolysis and gluconeogenesis.
Glycogenolysis is the process of breaking down glycogen into glucose, while gluconeogenesis is the formation of glucose from non-carbohydrate precursors.
These processes are crucial in maintaining blood glucose levels, especially during fasting or stress.
Step 2: Role of Glucagon.
Glucagon is a hormone produced by the alpha cells of the pancreas.
It promotes glycogenolysis and gluconeogenesis in the liver.
When blood glucose levels drop, glucagon is released to stimulate these processes, thereby raising blood glucose levels.
Step 3: Comparing other options.
Insulin: Insulin works oppositely to glucagon.
It promotes glycogenesis (the formation of glycogen from glucose) and lowers blood glucose levels.
Aldosterone: Aldosterone is a hormone involved in regulating sodium and water balance, not glucose metabolism.
ACTH (Adrenocorticotropic hormone): ACTH stimulates cortisol release from the adrenal glands but does not directly promote glycogenolysis or gluconeogenesis.
Thus, the correct answer is (C) Glucagon.