A nurse is caring for a client who has a prescription for NPH insulin 10 units and regular insulin 15 units subcutaneously. After injecting 10 units of air into the NPH insulin vial, which of the following actions should the nurse take next?

A. Inject 15 units of air into the regular insulin vial: After injecting air into the NPH vial without drawing up the medication, the next step is to inject air into the regular insulin vial. This maintains the correct order and prevents contamination of the regular insulin with the cloudy NPH insulin. B. Withdraw 10 units of NPH insulin: NPH insulin should not be withdrawn first because it is cloudy and could contaminate the regular insulin if mixed incorrectly. Regular insulin, which is clear, should always be drawn up before NPH when mixing in the same syringe. C. Verify the dosage with another nurse: Verifying insulin doses with another nurse is necessary but is typically done after the insulin is prepared and drawn up. At this stage, the immediate step is to complete proper air injection into both vials before drawing any insulin. D. Place the cap over the needle: Recapping needles increases the risk of accidental needlestick injuries and should be avoided unless absolutely necessary. There is no need to recap at this stage in the insulin preparation process.