Which of the following provides the most accurate measure of GFR?

Ans. C. Inulin clearancea. Inulin clearance is the standard for measuring GFR.b. Because Inulin is neither secreted nor reabsorbed, only filtered, so rate of clearance is equal to GFR.c. (Creatinine is slightly secreted from the peritubular capillaries into the tubules)d. PAH clearance is used to measure renal plasma flow, not GFR.