Question

The end of the paleozoic era was signaled by

Answer 1

The correct answer for the question that is being presented above is this one: "B. mass extinction of land and sea animals." The end of the paleozoic era was signaled by mass extinction of land and sea animals.

Here are the following choices:
A. the development of humans
B. mass extinction of land and sea animals
C. the development of organisms with hard parts
D. both a and b