A nurse is caring for a client who has preeclampsia and is being treated with magnesium sulfate IV. The client's respiratory rate is 10/min and deep-tendon reflexes are absent. Which of the following actions should the nurse take?

A. Discontinue the medication infusion: A respiratory rate of 10/min and absent deep-tendon reflexes are signs of magnesium sulfate toxicity. These symptoms require immediate discontinuation of the infusion to prevent respiratory arrest. The nurse should also prepare to administer calcium gluconate, the antidote, per protocol. B. Prepare for an emergency cesarean birth: While severe maternal complications can lead to an emergency delivery, the current concern is magnesium toxicity, which must be managed immediately to stabilize the mother. Delivery is not indicated at this point unless there are also signs of fetal or maternal compromise unrelated to magnesium. C. Assess maternal blood glucose: While blood glucose can be affected by various conditions, it is not directly related to the signs of magnesium overdose. The immediate concern is the client's respiratory status and neurological compromise due to the medication. D. Place the client in Trendelenburg position: Trendelenburg positioning is used to manage hypotension or promote venous return but is not appropriate or helpful in managing magnesium toxicity. It does not address the respiratory depression or neuromuscular suppression present in this situation.