Which statement best describes urine composition?

• A. 95% water, urea and uric acid, trace amounts of amino acids
• B. 70% water, creatinine and bilirubin
• C. 99% water, glucose
• D. 85% water, electrolytes only

Answer: (A)

Urine is produced as the kidneys filter blood, removing wastes while reabsorbing what the body still needs. The fluid is mainly water, about 95%, with dissolved wastes such as urea and uric acid, plus small amounts of other substances like amino acids, creatinine, and electrolytes. The option that lists about 95% water, with urea and uric acid and trace amino acids, matches this typical composition. The other choices either misstate how much water is present or include substances not normally found in urine in significant amounts (for example, glucose or bilirubin) or oversimplify the mix by implying only electrolytes.