What causes the atmosphere to divide into spherical layers? 

A)  the concentration of oxygen in each layer 
B)  the temperature changes from variations in absorption of solar energy 
C)  the concentration of ozone in each layer 
D)  the density of each layer

The atmosphere divides into spherical layers due to temperature changes resulting from variations in the absorption of solar energy. As solar energy passes through the atmosphere, some of it is absorbed by gases, such as ozone and water vapor, which causes temperature changes at different altitudes. This results in the formation of distinct layers in the atmosphere. The temperature changes also affect the density of each layer, but it is not the main cause for the division of the atmosphere into spherical layers. The concentration of oxygen and ozone in each layer can play a role in the chemical composition of the atmosphere, but they do not cause the layering.