A nurse is teaching a client how to draw up regular insulin and NPH insulin into the same syringe. Which of the following instructions should the nurse include?

A. Inject air into the regular insulin first: When mixing insulin, the correct procedure is to inject air into the NPH insulin vial first, followed by injecting air into the regular insulin vial. This technique helps prevent contaminating the regular insulin vial with NPH insulin. B. Draw up the NPH insulin into the syringe first: The correct order is to draw up regular insulin (clear) first, then NPH insulin (cloudy). Drawing up NPH insulin first can contaminate the regular insulin, leading to incorrect doses. C. Shake the NPH insulin until it is well mixed: NPH insulin should be gently rolled between the hands to mix it, not shaken. Shaking can create bubbles and cause improper mixing of the suspension, making it less effective. D. Discard regular insulin that appears cloudy: Regular insulin should always be clear. If it appears cloudy or discolored, it should be discarded. This indicates that the insulin has been compromised and may not be safe to use. NPH insulin, however, is naturally cloudy and should be used as directed.