What is the urinary system composed of?

• A. liver, kidneys, ureters, bladder
• B. kidneys, ureters, urinary bladder, urethra
• C. lungs, heart, kidneys, ureters
• D. kidneys, liver, urethra, bladder

Answer: (B)

The urinary system includes the kidneys, which filter waste from the blood; the ureters, which carry that urine to the bladder; the bladder, which stores urine; and the urethra, through which urine exits the body. Other organs listed belong to different body systems (the liver is part of digestion and metabolism, while the lungs and heart belong to respiratory and circulatory systems). The set that includes all four urinary components—kidneys, ureters, bladder, and urethra—covers the entire system, making it the best choice. The other options either include a non-urinary organ or omit one of the urinary organs.