Renal calculi are kidney stones. Which option correctly identifies this condition?

• A. Urinary tract infections.
• B. Bladder stones.
• C. Kidney stones.
• D. Ureteral stones.

Answer: (C)

Renal refers to the kidney, and calculi means stones. So renal calculi are stones that form in the kidney, i.e., kidney stones. The other options describe stones in different parts of the urinary tract or a different condition altogether: bladder stones occur in the bladder, ureteral stones form in the ureter, and a urinary tract infection is an infection of the urinary system, not a stone.