Although ozone is a pollutant in the ambient air, but in stratosphere it is valuable because it ahsorbs harmful

The correct option is UV-Radiations.

Ozone ($O_3$) plays two very different roles in our atmosphere depending on where it is located:
1. In the troposphere (ambient air): Ground-level ozone is a major air pollutant and a key component of smog, causing respiratory issues and damage to vegetation.
2. In the stratosphere (ozone layer): Located about 10 to 50 kilometers above the Earth's surface, ozone is highly beneficial. It acts as a natural shield that absorbs the majority of the Sun's high-energy ultraviolet (UV) radiation, specifically UV-B and UV-C rays.

Without the stratospheric ozone layer absorbing harmful UV-Radiations, these high-energy waves would reach the Earth's surface, leading to severe biological consequences such as increased rates of skin cancers, cataracts, and disruption of ecosystems.