A nurse is monitoring a client who is receiving magnesium sulfate for severe preeclampsia. The client asks, "How will I know if the medication is working?" Which response by the nurse is most appropriate?

A. "We will monitor your blood pressure to see if it decreases." While magnesium sulfate may have a mild antihypertensive effect, it is not primarily given to lower blood pressure; antihypertensives are used for that purpose. B. "We will check for a reduction in swelling and fluid retention." Edema in preeclampsia is due to capillary leakage and kidney dysfunction, not directly affected by magnesium sulfate. C. "We will assess for a decrease in seizure activity and improved reflexes." Magnesium sulfate is used primarily as a seizure prophylaxis in preeclampsia by stabilizing the central nervous system and reducing hyperreflexia and clonus, which are signs of worsening preeclampsia. D. "You should feel less pain and have fewer headaches." While magnesium sulfate can improve symptoms, it is not an analgesic and does not directly relieve pain.