A nurse is reinforcing teaching with an adolescent about self-administration of insulin. Which of the following instructions should the nurse include?

A. "You should chill your medication before administration." Insulin should not be chilled before administration. It should be stored in a cool place, but administering insulin directly from the refrigerator can cause discomfort. B. "You should rotate sites when administering the medication." Rotating injection sites helps prevent tissue damage and the formation of lumps or scar tissue. It is recommended to rotate sites within the same area (e.g., abdomen, thigh, etc.) to ensure absorption and prevent complications. C. "You should administer your medication at a 45-degree angle." Insulin should generally be administered at a 90-degree angle for subcutaneous injection, not a 45-degree angle. A 45-degree angle may be appropriate. D. "You should administer your insulin into a muscle." Insulin should be administered subcutaneously (into the fat layer just under the skin), not into the muscle. Injecting insulin into a muscle can alter its absorption rate and may cause irritation or pain.