A client with type 2 diabetes mellitus (DM) is admitted to the hospital for uncontrolled DM. Insulin therapy is initiated with an initial dose Isophane suspension insulin at 0800. At 1600, the client reports having diaphoresis, rapid heartbeat, and feeling shaky. Which should the nurse do first?

A. While oxygen saturation is important, it's not the priority in this situation. The client's symptoms strongly suggest hypoglycemia. B. The client's symptoms of diaphoresis, rapid heartbeat, and shakiness are classic signs of hypoglycemia. Therefore, the first action should be to confirm this diagnosis by checking the blood glucose level. C. Administering glucose before confirming hypoglycemia can be dangerous. If the client is hyperglycemic, giving them sugar will worsen their condition. D. Providing food without confirming hypoglycemia is not appropriate.