In a series of rock layers, a geologist finds fossils of a pine trees and oak trees in layers that are 1.0 m and 1.5 m deep. however, in a layer that is 2.0 m deep, he finds fossils of tropical plants and trees.

which explains his findings?

a.
the ancient climate remained hot.

b.
the continent remained in the tropics.

c.
the continent shifted toward the mid-latitudes and polar regions.

d.
the continent shifted toward the tropics.