In the kidneys, both useful substances and wastes are removed from the blood by? A. reabsorption. B. excretion. C. dialysis. D. filtration

The correct answer for the question given above would be option D. In the kidneys, both useful substances and wastes are removed from the blood by filtration. In this process, the fluid in the blood is being filtered across the capillaries of the glomerulus and into the urinary space of the Bowman's capsule.