Answer : 2. "Stratosphere"
Explanation :

Answer: B) Stratosphere Explanation: The ozone layer is a region of Earth's Stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.   The Atmosphere is divided into 4 layers according to major changes in temperature. They are : 1. Troposphere, 2. Stratosphere, 3. Mesosphere  and 4. Thermosphere. The farther away from earth, the thinner the atmosphere gets.