The rubber stopper on a vial may be sterilized by:
A- Spraying the top of the vial with isopropyl alcohol and allowing it to dry before needle entry.
B- Spraying the top of the vial with isopropyl alcohol and do the needle entry before the alcohol dries.
C- Swabbing the top of the vial with a single, unused sterile alcohol wipe in the laminar airflow workbench and allowing to dry before entry
D- Swabbing the top of the vial with several firm strokes in the same direction using an unused portion of an alcohol swab on each pass
