What happens to nearly all of the uv radiation that enters the atmosphere? (site 1)?

Some of the sun's energy, though, is reflected from our atmosphere and sent back into space. -Can contain some heat and reflect out some of the heat. What happens to nearly all of the UV radiation that enters the atmosphere? The Ozone layer absorbs most of the UV radiation that enters the atmosphere.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

"a.) well–developed vascular system."