Red-Green Color Blindness Is a Sex-Linked Recessive Trait in Humans

Multiple Choice

Red-green color blindness is a sex-linked recessive trait in humans.The normal,dominant allele is symbolized with X^N,and the recessive allele is symbolized with Xⁿ.Two people with normal color vision have a color-blind son.What are the genotypes of these parents?

A) X^NXⁿ and XⁿY
B) XⁿXⁿ and X^NY
C) X^NX^N and XⁿY
D) X^NX^N and X^NY
E) X^NXⁿ and X^NY