A nurse is caring for a client who has severe preeclampsia and is receiving magnesium sulfate intravenously. The nurse discontinues the magnesium sulfate after the client displays toxicity. Which of the following actions should the nurse take?

A. The supine position can reduce venous return and decrease cardiac output in pregnant clients; the left lateral position is preferred. B. Methylergonovine is contraindicated in clients with hypertension or preeclampsia because it can cause severe vasoconstriction and increase blood pressure. C. Dextrose IV bolus is used to treat hypoglycemia, not magnesium toxicity. D. Calcium gluconate is the antidote for magnesium sulfate toxicity. It reverses respiratory depression, bradycardia, and cardiac conduction issues caused by excessive magnesium levels.