A nurse is caring for a client who will have blood sampling for a serum creatinine level and asks what this test shows. Which of the following responses should the nurse make?

"You'll have to ask your doctor."

"This test will tell if you have severe renal impairment or a disease."

"We'll find out if any medications, such as steroids, are interfering with your kidney function

"This test will tell your doctor how your kidneys are functioning."