The Fruit Fly Cross Shown Here Analyzes the Transmission of Two

The fruit fly cross shown here analyzes the transmission of two genes in the X chromosome. The male parent has mutant alleles for both the white gene (w^-) and the crossveinless gene (cv^-) . The female parent has nonmutant forms of these genes (w⁺ and cw⁺) . A cross between siblings of the F₁ generation-a red-eyed, crossveined female and a red-eyed, crossveined male-generates F₂ progeny. Examine the genotype of the F₂ male progeny. Notice that the progeny fall into two groups. Refer to the figure below when answering the following question. Which of the statements below does NOT explain why the male progeny from the F₁ cross are used for linkage analysis?

A) The phenotype of F₂ males reveals the genotype of the X chromosome they inherited from their mother.
B) All four possible classes of maternal gametes are observed in the F₂ male progeny in a 1:1:1:1 ratio, which indicates that the two genes undergo independent assortment.
C) The lack of independent assortment indicates that the two genes are linked in the X chromosome.
D) The Y chromosome in the male offspring allows the genotype of each X chromosome inherited from the mother to be observed in the male phenotype.