A nurse is preparing to mix NPH insulin and insulin aspart in a single syringe for a client who has type 2 diabetes mellitus. Which sequence should the nurse follow?

Air into NPH → air into aspart → withdraw aspart → withdraw NPH

Air into aspart → air into NPH → withdraw NPH → withdraw aspart

Air into NPH → withdraw NPH → air into aspart → withdraw aspart

Air into aspart → withdraw aspart → air into NPH → withdraw NPH