Option C, animals moved from the sea to the land is the right answer.
The Paleozoic Era in the history of the earth was a time of major change on Earth. This was the period that ran about 542 to 251 million years ago. The period commenced with the split of a single super-continent and the development of another. Plants grew extensively. Moreover, the primary vertebral animals conquered the land.
I am sure that it is not a or b and pretty sure that it isn't d so it is c
1 - introduced to a habitat similar to their own
3 - outcompete native species
4 - generally have no native predators
6 - often have high reproductive rates
8 - can tolerate a range of conditions