Within this layer, ultraviolet radiation (UV) causes ionization.
The thermosphere begins about 85 kilometres above the Earth.
At these high altitudes, the residual atmospheric gases sort into stratum according to molecular mass.
Thermospheric temperatures increase with altitude due to absorption of highly energetic solar radiation.
Ionosphere and magnetosphere, regionsof Earth'satmospherein which the number of electrically charged particles—ions and electrons are large enough to affect the propagation of radio waves.
Therefore, option C is correct.