This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Excretory System (Kidney, Bladder) Acid-Base Balance, Subject name: Physiology
[{'content': 'Renal filtration fraction is calculated as \nSelect and explain. \nA. Renal plasma flow (RPF)/GFR, B. GFR/RPF, C. (RPF x GFR)/ Total Blood flow, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Renal filtration fraction= GFR/(RPF) The filtration fraction, is normally 0.16-0.20. The GFR varies less than the RPF. When there is a fall in systemic blood pressure, the GFR falls less than the RPF because of efferent aeriolar constriction, and consequently the filtration fraction rises.', 'role': 'assistant'}]