Final answer:
The stratosphere contains the ozone layer, which shields us from ultraviolet light.
Step-by-step explanation:
The correct answer is a) Ozone. The stratosphere contains the ozone layer, which shields us from ultraviolet light. Ozone, a form of oxygen with three atoms per molecule, is a good absorber of ultraviolet light and protects the surface from the Sun's dangerous ultraviolet radiation. This protection is important becauseUV-B radiation causes skin cancer and can lead to genetic damage. The ozone layer has historically protected the Earth from harmful UV rays, although its protection has been diminishing due to stratospheric ozone depletion.