Correct Option: D

The exosphere is the outermost layer of Earth’s atmosphere. It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km where it merges into the solar wind. This layer is mainly composed of extremely low densities of hydrogen, helium and several heavier molecules.The exosphere is located too far above Earth for any meteorological phenomena to be possible.