In the vertical structure of the atmosphere, which one is the lowest layer?

The layer of atmosphere having lowest temperature is

Ozone layer, which absorbs the ultra-violet radiation, is found in which one of the following layers of the atmosphere?

Which layer of Atmosphere is used for Telecommunication?

The Earth's atmosphere is mainly heated by which one of the following?

Which one of the following layers of the atmosphere is responsible for the deflection of radio waves?