A nurse is caring for an older adult who is diagnosed with type 2 diabetes. The patient is prescribed oral medication for diabetes. The nurse can expect that which of the following medications is prescribed as a first-line therapy?

A. Insulin: Insulin therapy is generally reserved for patients with type 2 diabetes who are unable to achieve adequate glycemic control with oral medications or who have severe hyperglycemia. It is not typically used as a first-line treatment in older adults unless oral agents are contraindicated. B. Sulfonylureas: Sulfonylureas stimulate insulin secretion but pose a higher risk of hypoglycemia, particularly in older adults with irregular meal patterns or impaired renal function. They are often used as second-line agents after metformin. C. Chlorpropamide: Chlorpropamide is an older sulfonylurea that is no longer recommended for older adults due to its long half-life and high risk of prolonged hypoglycemia. Its use has largely been discontinued in favor of safer, more effective alternatives. D. Metformin: Metformin is the first-line oral medication for type 2 diabetes because it effectively lowers blood glucose, promotes weight control, and carries a low risk of hypoglycemia.