This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'What is the clearance of a substance when its concentration in the plasma is 10mg/dl, its concentration in the urine is 100mg/dl and urine flow is 2ml/min? \nSelect and explain. \nA. 0.2ml/min, B. 2ml/min, C. 20ml/min, D. 200ml/min', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The Clearance of a Substance &;X&; is equal to the concentration of substance X in urine (UX) times the urine flow per unit of time (V) divided by the aerial plasma level of X (PX), or UXV/PX.This value is called the clearance of X (CX).Coming to the above question: 100 mg/dl X 2 ml/min / 10 mg/dl = 20 ml/min.', 'role': 'assistant'}]