Which contributing factors cause the thermosphere to be warmer than the mesosphere?
A. Gases are more dense in the thermosphere and absorb energy easily.
B. Sunlight is reflected by the abundant gases, oxygen and nitrogen, in the mesosphere.
C. The abundance of hydrogen gas causes explosions, sending heat into the stratosphere.
D. Ultraviolet radiation is absorbed, and fewer air molecules cause the thermosphere to heat quickly.
