This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nephrotic and Nephritic syndrome, Subject name: Medicine
Clinical features of Uraemia will appear when GFR is < ___ml/min/ 1.73 m2? 
Select and explain. 
A. 15, B. 30, C. 45, D. 60
A: 15
Answer: A: 15 
Explanation: Development of: Uraemia <15 ml/min/1.73m2 Acidosis, hyperkalemia 15-29 ml/min/1.73m2 Anemia 30-59 ml/min/1.73m2 Hypeension 60-89 ml/min/1.73m2