Two heterozygous flies are crossed. show the cross, list the genotype

A heterozygous trait can be described as a trait in which both the alleles of a gene are different. A homozygous trait can be described as a trait in which both the alleles of a gene are similar.

Consider two flies which have heterozygous alleles for a trait (Ww). The cross between these species is shown below:

         W         w

W       WW     Ww

w         Ww     ww

The results show that 25% of the offsprings will be homozygous dominant (WW)  for the trait. 50% of the offsprings will be heterozygous dominant for the trait (Ww). 25% of the offsprings will be recessive.  

i think the answer is a.keratin is the pigment responsible for skin color.