Australia's animal populations adapted to a unique ecosystem after separation from other plates.
Answer: Option D
Explanation:
Australia has unique species of animals compared to the rest of the world because of it's long time separation from the other continents which led to the adaptation of the animals on this continent to the unique ecosystem of Australia resulting in some unusual Australian animals. The animals which were originally on Australian landmass had no more contact with the animals in other part of the world, thus they developed independently.
