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: Pediatrics
In chronic renal failure : a) Urine output is more than 3 litres per dayb) Urine concentration is decreasedc) Sodium conservation is poord) Polycythemia is present 
Select and explain. 
A. a, B. c, C. bc, D. ad
C: bc
Answer: C: bc 
Explanation: None