<span>Answer: C. Time of ancient life.
Paleozoic comes from Greek word palaios which means "old" or "ancient", and zoe which means "life".
it could be translated as "</span>Time of ancient life". The range of Paleozoic era is from <span>541 to 251 million years ago that could be divided into 6 smaller periods.</span>
I believe the correct answer from the choices listed above is option D. Based on the time scale, it would be that <span>the atmosphere was formed after microscopic life appeared on Earth that is the correct inference. It is very clear in the picture as the microorganisms appear before the atmosphere. Hope this answers the question. </span>