Final answer:
The breakdown of glycogen is stimulated by low levels of insulin and low levels of glucose, which prompts the secretion of glucagon. This hormone facilitates the conversion of glycogen to glucose to raise blood glucose levels.
Step-by-step explanation:
The breakdown of glycogen in the human body is a process that primarily occurs when there is a need to increase blood glucose levels. This typically happens when blood glucose levels are low, signaling a need for additional glucose to be released into the bloodstream for energy. In this scenario, the hormone responsible for the breakdown of glycogen is glucagon, which is released by the pancreas. The correct answer to which of the aforementioned factors can lead to the breakdown of glycogen is C. Low levels of insulin and D. Low levels of glucose. Both of these conditions signal the pancreas to release glucagon, which in turn triggers the conversion of glycogen to glucose in the liver, increasing blood glucose levels.
It is important to note that high levels of insulin promote the storage of glucose in the form of glycogen, rather than its breakdown. Hence, options A. High levels of insulin and B. High levels of glucose are not associated with the breakdown of glycogen but with its synthesis and storage.