A nurse is caring for a client who is experiencing warfarin toxicity. Which of the following medications should the nurse administer?

A. Protamine sulfate: Protamine sulfate is used to reverse the effects of heparin, not warfarin. Administering it in warfarin toxicity would not effectively counteract the anticoagulant effect and could delay appropriate treatment. B. Vitamin K: Vitamin K is the antidote for warfarin toxicity. It promotes synthesis of clotting factors II, VII, IX, and X, which are inhibited by warfarin, helping to restore normal coagulation and reduce the risk of bleeding. C. Calcium gluconate: Calcium gluconate is primarily used to treat hypocalcemia or cardiac effects of hyperkalemia. It does not reverse warfarin-induced anticoagulation and would not address the underlying risk of bleeding. D. Acetylcysteine: Acetylcysteine is an antidote for acetaminophen toxicity and works by replenishing glutathione. It has no effect on warfarin metabolism or clotting factor synthesis, making it inappropriate for this scenario.