Marsupials are found in North America and Australia, but they would not have been able to swim across the ocean. According to scientists, how did this group of organisms come to live on two separate continents?

A. Marsupials used to have adaptations that allowed them to swim but lost these adaptations over time.
B. The two groups of marsupials evolved independently of one another on two separate continents.
C. The continents were once connected, and marsupials were able to migrate over the land.
D. The oceans were shallow in prehistoric times, which allowed the marsupials to travel from one continent to another.