Kidney Stones are Primarily Composed of Which Substances That Settle

Question

Kidney stones are primarily composed of which substances that settle out of urine?  
A) Potassium salts
B) Uric acid and calcium
C) Urea and potassium
D) Phosphates and amino acids
E) Fatty acid salts

Accepted Answer

Kidney stones are primarily composed of uric acid and calcium that settle out of urine, forming solid masses. Potassium salts, urea and potassium, phosphates, and amino acids can also be found in kidney stones but are not the primary substances. Fatty acid salts are not commonly found in kidney stones.