In which of the following layer of atmosphere there is more thickness of ozone:

Explanation

Ozone, O3, is a gas having low boiling point. It is present in small concentrations throughout the atmosphere.The amount of ozone in the atmosphere is expressed in Dobson units (DU). The normal amount of overhead ozone is about 350 DU. The ozone layer, 25 - 28 km high, in the stratosphere surrounds the globe and filters most of the harmful ultraviolet (UV) rays in the sunlight before they could reach on the earth.