The nurse suspects gastrointestinal (GI) bleeding in a 62-year-old patient with kidney disease. Which finding in the patient's blood report supports the nurse's suspicion?
A. Serum creatinine value of 0.7 mg/dL
B. Serum creatinine value of 1.1 mg/dL
C. Blood urea nitrogen (BUN) value of 25 mg/dL
D. Blood urea nitrogen (BUN)/creatinine ratio of 24