Answer  ---  (d) Ozone layer-Troposphere

As we know, the ozone layer or ozone shield is a region of the Earth's stratosphere that absorbs most of the sun's ultraviolet radiation. It has a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. Where the ozone layer, about 15 to 35 kilometers (9.3 to 21.7 mi) above the Earth, is found mainly in the lower part of the stratosphere.

The ozone layer was first discovered in 1913 by French physicist Charles Fabry and Henri Bison.