Why D is correct

Safe injection practice requires a new sterile needle and new sterile syringe for every entry into a vial and every injection. Multidose vials should be dedicated to a single client whenever possible to reduce transmission risk.

Nursing Priority: ASSESS medication preparation technique before administration. INTERVENE by using aseptic technique and a new needle and syringe every time. DELEGATE medication administration only if allowed by role and policy; injection preparation remains a licensed responsibility. ESCALATE any suspected unsafe injection practice through the chain of command immediately.

Why C is incorrect

Cleaning the stopper is correct but does not make client sharing safe. It does not replace the single-use syringe rule or preferred single-client dedication.

Why B is incorrect

Changing only the needle is unsafe. A used syringe can contaminate a vial even if a new needle is attached.

Why A is incorrect

Room location does not reduce contamination risk. Safe injection practice depends on sterile equipment and proper vial use, not geography.