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: Physiology
[{'content': 'What is the clearance of a substance, if its concentration in plasma in 10 mg%, concentration in urine is 100 mg% and urine flow is 2 ml/min \nSelect and explain. \nA. 0.2 ml/min, B. 0.2 ml/min, C. 2 ml/min, D. 20 ml/min', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Clearance = urine flow rate ✕ urine concentration / plasma concentration\n= 100 X 2 / 10\n= 20 ml/min', 'role': 'assistant'}]