Answer:
Organ level– an organ is a structure composed of at least two different tissue types that perform a specific function within the body. Examples include the brain, stomach, and liver. Complex functions begin to emerge at this level.
Explanation:
Outer core is the answer - Appex
The answer is B. Paleozoic
This era was the first era where insects, amphibians, and reptiles roamed the Earth.
Hope this helps!
The answer your looking for should be flowering plants
