If Two Otherwise Dissimilar Organisms Share Similar Genomic DNA,to What

If two otherwise dissimilar organisms share similar genomic DNA,to what would you attribute the genomic similarity?

A) The shared genes are ancient and probably no longer function within the altered physiological states of modern organisms.
B) The shared genes have evolved a number of times and have no phylogenetic significance.
C) The two taxa are more closely related than formerly believed.
D) The shared genes developed early in evolution and are likely to be applicable to a wide diversity of organisms.
E) DNA is not a reliable basis for phylogenetic decisions.