A nurse is caring for a client who is scheduled for a blood sampling for a serum creatinine level. The client asks the nurse, "What is the purpose for this test?" Which of the following responses should the nurse give?

A. "This test will inform your provider how your kidneys are functioning." Creatinine is a waste product from muscle metabolism and is excreted by the kidneys. Elevated creatinine levels indicate impaired kidney function. B. "This test will inform your provider if you have a thyroid disorder." Thyroid disorders are typically diagnosed with TSH, T3, and T4 tests, not creatinine. C. "This test will inform your provider if you have an infection." Infections are usually diagnosed with CBC (WBC count) or cultures, not creatinine. D. "This test will inform your provider if you are anemic." Anemia is diagnosed with hemoglobin and hematocrit (H&H), not creatinine levels.