The correct answer is (c). The ozone layer is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet radiation. It contains high concentrations of ozone (O3) relative to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. The ozone layer contains less than 10 parts per million of ozone, while the average ozone concentration in Earth’s atmosphere as a whole is about 0.3 parts per million. The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometers (12 to 19 mi) above Earth, although its thickness varies seasonally and geographically.
The troposphere is the lowest layer of Earth’s atmosphere, extending from the surface to an average height of about 12 kilometers (7.5 mi). It is the layer of the atmosphere where most weather occurs. The tropopause is the boundary between the troposphere and the stratosphere. The stratosphere is the second layer of Earth’s atmosphere, extending from the tropopause to an average height of about 50 kilometers (31 mi). It is the layer of the atmosphere where the ozone layer is located. The photosphere is the visible surface of the Sun. It is the layer of the Sun that emits visible light.