In the Human Genetic Disorder Alkaptonuria, Urine Turns Black Because

In the human genetic disorder alkaptonuria, urine turns black because of the presence of homogentisic acid in individuals with the trait.This is due to

A) the presence of large amounts of homogentisic acid in the diet.
B) failure of individuals with alkaptonuria to manufacture enzymes involved in the synthesis of homogentisic acid.
C) failure of wild-type individuals to manufacture enzymes involved in the synthesis of homogentisic acid.
D) failure of the kidneys to remove homogentisic acid from the urine.
E) failure of individuals with alkaptonuria to manufacture enzymes involved in the breakdown of homogentisic acid.