Concept:The pancreas secretes hormones that regulate blood glucose levels.Explanation:The hormones insulin and glucagon are produced by the islet cells of the pancreas.Insulin lowers blood glucose by promoting glucose uptake into cells.Glucagon raises blood glucose when the level is too low.Together, they keep blood glucose within a normal range.Among the options, the action of insulin clearly matches lowering blood glucose.Answer:C. Lower blood glucose level.