There Are a Group of 13 Related Species of Birds

There are a group of 13 related species of birds on a group of about 20 isolated oceanic islands. These species are grouped into four subgroups, with subgroup 1 evolving first (3 species) , subgroup 2 evolving second (1 species) , subgroup 3 evolving third (5 species) , and subgroup 4 evolving last (6 species) . If subgroup 4 evolved most recently, then which of the following statements is the most logical prediction?

A) Subgroup 4 should be limited to the six islands that most recently emerged from the sea.
B) The genomes of subgroup 4 should be more similar to each other than to the genomes of subgroup 3.
C) The species of subgroup 4 should share fewer anatomical homologies with each other than they share with the species of subgroup 4.
D) The chances of hybridization between two subgroup 4 species should be less than the chances of hybridization between two subgroup 3 species.