Question

the eastern coast of south america and the western coast of africa are separated by the atlantic ocean. if scientists find the same types of plant fossils on the eastern coast of south america and the western coast of africa, which of these would be the best conclusion?
a. at one time, the two continents were one landmass.

b. the oceans were formed after dinosaurs went extinct.

c. the climate in each continent has changed.

d. dinosaurs once lived in both of these regions.

Explanation:

This problem relates to the theory of continental drift. Finding the same plant fossils on two now - separated continents (eastern South America and western Africa) supports the idea that at one time the two continents were part of a single landmass, allowing plants to be distributed across them. Option B is incorrect as the formation of oceans and dinosaur extinction are not related to this fossil evidence. Option C is not supported as the fossil evidence points to continental movement, not just climate change. Option D is incorrect as the fossils are plant fossils, not dinosaur fossils.

Answer:

A. At one time, the two continents were one landmass.