Results of Biochemical Tests Indicate an Infant Has Phenylketonuria (PKU)

Results of biochemical tests indicate an infant has phenylketonuria (PKU) .The parents ask what PKU means.Correct responses would include all the following except PKU

A) is an enzyme deficiency resulting in the inability to metabolize phenylalanine.
B) is an inborn error of metabolism.
C) results from a chromosome abnormality called nondisjunction.
D) is transmitted as an autosomal-recessive disorder.