Question

the renal blood vessels enter and leave the kidney at the:
a cortex.
b renal papilla.
c medulla.
d hilum.

Explanation:

The hilum is the concave part of the kidney where the renal artery enters, the renal vein exits, and the ureter (which carries urine away from the kidney) also exits. The cortex is the outer layer of the kidney involved in filtration. The renal papilla is part of the medulla (inner part) and is related to urine collection. The medulla is involved in concentration of urine. So the renal blood vessels (artery and vein) enter and leave at the hilum.

Answer:

D. hilum