The correct answer of the given question above would be option D. The option that did not occur during the Cenozoic era is the formation of the ozone layer. The ozone layer has long been there before any era since it is part of the earth's atmosphere. Hope this answer helps. 
        
                    
             
        
        
        
<em>The function of skeletal muscles is to control the movement of internal organs. The skeletal muscle pulls the tendons attached to the bones.</em>
        
             
        
        
        
The answer is D its the right answer because on the moon there is not oxygen for it to reach that state
        
             
        
        
        
The answer is A. small nutrients
        
                    
             
        
        
        
Answer:
The reactions of cellular respiration can be grouped into three stages: glycolysis, the Krebs cycle (also called the citric acid cycle), and electron transport.
Explanation: Hope this helps you!