Explain why there are a large number of marsupial mammal species in australia and south america, two continents that were once connected.
a) ozone production
b) continental drift
c) the fifth mass extinction
d) the first mass extinction

I believe the correct answer from the choices listed above is option B. It is continental drift that helps explain why there are a large number of marsupial mammal species in Australia and South America, two continents that were once connected. It was a theory that explained how continents shift position on Earth's surface. Hope this answers the question.