A client is admitted to the hospital with deep vein thrombosis (DVT). An infusion of heparin is established. What nursing action best protects the client's safety if the antidote is needed?

Ensure that the client's cellphone is easily accessible.

Have two nurses independently monitor the client's heparin infusion.

Ensure that protamine sulfate is readily available.

Keep a preloaded syringe of vitamin K in the room.