A nurse is preparing to administer magnesium sulfate IV to a client who is experiencing preterm labor. Which of the following is the priority nursing assessment for this client?

A. Fetal heart rate should be monitored, but maternal safety takes priority because magnesium sulfate can depress maternal neuromuscular and respiratory function. B. Temperature is not directly affected by magnesium sulfate; it is important but not the priority. C. Bowel sounds are unrelated to magnesium sulfate toxicity and are a lower-priority assessment. D. Respiratory rate is the priority assessment because magnesium sulfate can cause respiratory depression. Monitoring the maternal respiratory rate ensures early detection of toxicity and protects maternal and fetal well-being.