This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
[{'content': 'pH of urine is \nSelect and explain. \nA. 7.10 - 7.40, B. 3 - 3.5, C. 4 - 6.5, D. 6.5 - 7.10', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Thats the normal ph of urine. Ref: guyton and hall textbook of medical physiology 12 edition page number: 503,504,505', 'role': 'assistant'}]