The correct option is B Inulin
Inulin and its analog sinistrin are used to help measure kidney function by determining the glomerular filtration rate (GFR). GFR is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. Inulin is of particular use as it is not secreted or reabsorbed in any appreciable amount at the nephron, allowing GFR to be calculated.