Why Does Urine Frequently Have an Acidic PH

Why does urine frequently have an acidic pH?

A) The kidneys filter and excrete H⁺ from the blood.
B) The kidneys produce H⁺ in the process of filtering the blood.
C) The blood has an acidic pH and the kidneys produce urine similar to the pH of the blood.
D) There is a high concentration of hydrochloric acid (HCl) in the urine, making it highly acidic.
E) The kidneys absorb H⁺ ions and excrete bicarbonate ions.