Red-green color blindness is due to a mutant gene in the X chromosome. An XX female with normal color vision and an XY male with normal color vision have a child with karyotype XXY who is color blind. The likely explanation is that the:
a. father was heterozygous for the color-blindness mutation.
b. mother was heterozygous for the color-blind mutation.
c. father had CNV of the color-blind mutation.
d. mother had CNV of the color-blind mutation.
e. None of the other answer options is correct