I think the answer is (e) but I'm not certain.
In Drosophila melanogaster the genes for yellow body colour and white eye colour are linked this means that:
a. They can produce only one phenotype
b. They cannot separate
c. They produce more parental types than recombinant types
d. They produce more recombinant types than parental types
e. They produce only homozygotes
1 answer
Although this is not my area of expertise, I would assume that anything "linked" cannot be separated.