Presence of ozone in the atmosphere is important because it absorbs

The correct answer is Option 2: ultraviolet-B radiations only.

The stratospheric ozone layer acts as a vital protective shield for life on Earth. Its primary atmospheric function is the absorption of harmful solar radiation. The scientific distinction between UV subtypes is crucial for this selection:

• UV-C: These are the most energetic and dangerous, but they are entirely absorbed by oxygen and ozone in the upper atmosphere.
• UV-B: These possess medium wavelengths that are biologically damaging, causing skin cancer, cataracts, and harm to marine ecosystems. The ozone layer is the only atmospheric constituent that absorbs the bulk of UV-B radiations.
• UV-A: These have the longest wavelengths and are largely not absorbed by ozone, reaching the Earth's surface almost entirely.

Since ozone specifically filters out the harmful UV-B spectrum while allowing UV-A to pass, and does not interact with infrared radiations (which relate to the greenhouse effect), Option 2 is the most accurate description of its protective role.