Which hormone is produced by the pancreas to lower blood sugar levels?

Insulin is the hormone produced by the pancreas that plays a crucial role in lowering blood sugar levels. When blood glucose levels rise after eating, the pancreas releases insulin into the bloodstream. Insulin facilitates the uptake of glucose by cells, where it can be used for energy or stored as glycogen in the liver and muscle tissues. This action helps to regulate blood sugar levels and maintain homeostasis in the body.

In contrast, other hormones listed serve different functions. Glucagon, for instance, works in opposition to insulin by raising blood sugar levels when they drop too low. Cortisol is primarily involved in stress responses and helps regulate metabolism, but it tends to increase blood sugar levels rather than lower them. Thyroxine, produced by the thyroid gland, is important for regulating metabolism and energy levels but does not directly influence blood sugar levels. Thus, insulin is the primary hormone responsible for lowering blood sugar, making it the correct answer.