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?

Marsupials come to live on two separate continents when both the continents were attached to each other.

Marsupials are the group of organisms that come to live on two separate continents long time ago when the both continents i.e. North America and Australia were joined or attached to each other. The supercontinent named Pangea began to break apart about 200 million years ago which results in the formation of continents.

Before this broken, the Marsupials move to the Australian part from the North American part so we can conclude that Marsupials come to live on two separate continents when both the continents were attached to each other.

Learn more about supercontinent here: link

i think that d. wind is the answer.   i missed the question when i answered a. currents.