Refer to the Following Information to Answer the Questions Below

Refer to the following information to answer the questions below.
Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. It apparently lived in arid regions, and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous. The dicynodonts had two large tusks, extending down from their upper jaws; the tusks were not used for food gathering, and in some species were limited to males. Food was gathered using an otherwise toothless beak. Judging from the fossil record, these pig-sized organisms were the most common mammal-like reptiles of the Permian.
-Which of these is the most likely explanation for the existence of dicynodont fossils on modern-day Antarctica?

A) They arrived there aboard "rafts" of vegetation, and quickly adapted to the bitterly cold climate.
B) Earth's polar regions were once so warm (especially immediately after the "snowball Earth period") that reptiles and mammal-like reptiles flourished there.
C) The landmass that is now the Antarctic continent was formerly located at a more-northerly position, and was also united to other landmasses.
D) Dicynodonts originated on the island continent of Antarctica and went extinct as the continent migrated to its current position at the South Pole.