Answer: B. Serum creatinine 3.0 mg/dL
Explanation: Creatinine is a byproduct of protein metabolism and is excreted from the body through the kidneys. An elevated serum, creatinine level, therefore, can be an indication that the kidneys are not functioning. The nurse should identify that the adolescent’s serum creatinine level is higher than the expected reference range of 0.4 to 1.0 mg/dL for an adolescent and can indicate rejection of the kidney.