A nurse is collecting data from a client who has heart failure, prior to the administration of furosemide. For which of the following findings should the nurse withhold the medication?

A. An oxygen saturation of 95% is within normal limits and does not require withholding furosemide. B. A serum sodium level of 140 mEq/L is normal; furosemide can lower sodium, but this value alone does not necessitate holding the medication. C. A blood pressure of 80/40 mm Hg is significantly low (hypotension). Furosemide is a potent diuretic that can further lower blood pressure and reduce perfusion to vital organs, so the nurse should withhold the medication and notify the healthcare provider. D. A serum potassium level of 4.8 mEq/L is within the normal range (3.5–5.0 mEq/L); monitoring is important because furosemide can cause hypokalemia, but this level does not require withholding the drug.