Question

what causes the secretion of insulin by the pancreas? normal blood glucose concentration. increased blood glucose concentration. decreased blood glucose concentration.

Explanation:

Insulin is a hormone that helps regulate blood - glucose levels. When blood glucose levels rise (after a meal for example), the pancreas secretes insulin to lower the blood glucose levels by promoting glucose uptake into cells. Normal blood glucose levels do not trigger insulin secretion, and decreased blood glucose levels would not cause insulin release as insulin's function is to lower blood glucose.

Answer:

Increased blood glucose concentration.