. Ionosphere is also known as
D: None of the above
Our atmosphere is divided into different layers based on the composition of gasses.
Outermost is the exosphere, then comes the thermosphere, mesosphere, stratosphere, and troposphere.
These layers protect us from the UV radiations coming from the sun.
Ionosphere is the secondary layer of the thermosphere.
It is so named because of the presence of ions that reflect the radio waves back to the earth surface.
The correct answer option is b, thermosphere.