Answer:
D. It needs to have urine in it
Step-by-step explanation:
They are located just below the rib cage, one on each side of your spine. Healthy kidneys filter about a half cup of blood every minute, removing wastes and extra water to make urine. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of your bladder. The fluid that is filtered out from the blood then travels down a tiny tube-like structure called a tubule. The tubule adjusts the level of salts, water, and wastes that will leave the body in the urine. Filtered blood leaves the kidney through the renal vein and flows back to the heart.