A nurse is teaching a client who has a new diagnosis of Type 1 diabetes mellitus about self-administration of insulin. Which of the following instructions should the nurse include?

Rationale: A. Use each syringe up to six times: Insulin syringes are designed for single use to maintain sterility and prevent infection. Reusing syringes can increase the risk of contamination, dull needles, and lead to lipodystrophy at the injection site. B. Pull back on the plunger after injecting the insulin: Aspiration after subcutaneous insulin administration is not recommended. It causes unnecessary discomfort and has no clinical benefit, as blood return is rare in subcutaneous tissue. C. Store the current bottle of insulin at room temperature: Once in use, an insulin vial can be kept at room temperature for up to 28 days to reduce injection discomfort. Keeping the insulin at room temperature also prevents degradation from repeated refrigeration and warming. D. Massage the injection site after removing the needle: Massaging the site is discouraged because it can alter insulin absorption rates and increase the risk of hypoglycemia. Gentle pressure may be applied if bleeding occurs, but rubbing the site should be avoided.