Hi!
It would be D, because trilobites were aquatic.
Hope this helps!
im pretty sure the answer is going to most likely be A: decomposing dead plants and animals
The best answer would be "research reasons why species change over long periods of time"
if not i apologize but this is my best guess<span />
D because it reflects all other colors
A) germination, there is no plant embryo before pollination
