This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
A stage IV kidney disease is suspected in a lady with anaemia and progressive malnutrition. Which of the following renal parameters could be TRUE for her condition? 
Select and explain. 
A. 60-89 GFR, mL/min per 1.73 m2, B. 30-59 GFR, mL/min per 1.73 m2, C. 15-29 GFR, mL/min per 1.73 m2, D. < 15 GFR, mL/min per 1.73 m2
C: 15-29 GFR, mL/min per 1.73 m2
Answer: C: 15-29 GFR, mL/min per 1.73 m2 
Explanation: When GFR progresses to stages 3 and 4, viually all organ systems are affected. The most evident complications include anemia and associated easy fatigability; decreasing appetite with progressive malnutrition; abnormalities in calcium, phosphorus, and mineral-regulating hormones, such as 1,25(OH) 2D3 (calcitriol) and parathyroid hormone (PTH). Ref: Harrisons Principles of Internal Medicine, 18th Edition, Page 2308