Answer:
A. absorption of ultraviolet rays from the Sun
Step-by-step explanation:
The thermosphere helps protect and regulate Earth's temperature by absorbing much of the UV radiation and X-rays emitted by the Sun. When the Sun is most active, the thermosphere heats up and increases in size, increasing its protective power.
Just like in the oceans, the Earth's atmosphere experiences waves and tides that help move energy within it. The winds and the general circulation of the thermosphere are strong drivers of these tides and waves.