Question

why is the ozone layer important for life on earth?
it blocks harmful ultraviolet radiation.
it reflects visible light.
it absorbs carbon dioxide.
it prevents acid rain.

Explanation:

The ozone layer is important because it absorbs and scatters harmful ultraviolet (UV) radiation from the sun. UV radiation can cause skin cancer, cataracts, and harm ecosystems. The first option: blocking UV is its key role. Reflecting visible light is not its function (ozone is transparent to visible light). Absorbing CO₂ is not related to ozone (CO₂ absorption is by plants, oceans, etc.). Preventing acid rain is related to pollutants like SO₂/NOₓ, not ozone. So the correct reason is it blocks harmful ultraviolet radiation.

Answer:

A. It blocks harmful ultraviolet radiation