What structure is used to transport blood into the kidneys to be filtered? A. Renal artery B. Renal pelvis C. Ureters D. Renal vein

The structure that is used to transport blood into the kidneys to be filtered is the Renal artery (A). Here's a step-by-step explanation:

1. The heart pumps oxygenated blood around the body through arteries.
2. The renal artery, a branch of the aorta (the body's main artery), carries a large portion of this blood to the kidneys for filtration.
3. Once in the kidneys, the renal artery divides into many smaller blood vessels, eventually becoming a network of tiny capillaries.
4. These capillaries come into close contact with the nephrons, the functional units of the kidney. Here, waste products and excess substances are filtered out from the blood.
5. The filtered blood then leaves the kidneys via the renal vein, while the waste products form urine, which travels to the bladder via the ureters.