Final answer:
The production of insulin triggered by an increase in blood glucose levels is a result of a negative feedback loop. The correct answer is option a).
Step-by-step explanation:
A rise in blood glucose levels triggers the release of insulin from the pancreas. This mechanism of hormone production is stimulated by negative feedback. When glucose levels are high, insulin is released to facilitate the uptake of glucose by cells and its conversion to glycogen in the liver, effectively lowering the blood glucose levels.
As glucose concentrations decrease, the stimulus for insulin secretion diminishes, thereby decreasing insulin release. Conversely, when blood glucose levels are too low, the hormone glucagon is produced, promoting the conversion of glycogen back to glucose.
Furthermore, insulin facilitates cells in using glucose for energy and storing excess glucose for later use. This intricate balance maintains the body's glucose levels within a narrow range. If insulin activity is impaired, as in diabetes mellitus, blood glucose levels increase, leading to hyperglycemia.