This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Kidney Disease and Uremia, Subject name: Medicine
[{'content': 'Clinical features of CRF/uraemia appear when renal function is reduced to - \nSelect and explain. \nA. 70%, B. 50%, C. 30%, D. 20%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans- C. Appear at stage 3 Prominent at Stage 5', 'role': 'assistant'}]