The Nurse Is Preparing Two Medications from Separate Vials in One

The nurse is preparing two medications from separate vials in one syringe.After injecting air into vial A,which action by the nurse is the most appropriate?

A) Changing needles and injecting air into vial B
B) Changing needles,injecting air into vial B,and then withdrawing medication from vial A
C) Injecting air into vial B,changing needles,and withdrawing medication from vial A
D) Changing needles,injecting air into vial B,withdrawing medication from vial B,and then withdrawing medication from vial A