Colour Vision Depends Upon the Dominant Alleles of Three Genes

Multiple Choice

Colour vision depends upon the dominant alleles of three genes: the R gene and the G gene are both on the X chromosome,while the B gene is autosomal.Recessive mutations in any of the three genes can cause colour blindness.Suppose a colour-blind man marries a colour-blind woman and all of their offspring have normal vision.What is the genotype of the woman?

A) RRGGbb
B) RRggBB
C) rrGGbb
D) RRggBB or RRGGbb
E) rrGGbb or rrggBB