Where is ozone found in the atmosphere?

• A. In the troposphere at sea level
• B. Very thinly dispersed throughout the stratosphere
• C. Concentrated only over urban areas
• D. In the mesosphere and thermosphere

Answer: (B)

Ozone is predominantly found in the stratosphere, where it is present in a layer that absorbs the majority of the sun's harmful ultraviolet radiation. This layer of ozone is crucial for protecting life on Earth from UV radiation that can lead to skin cancer and other health issues, as well as harm to the environment.

The second option reflects the correct understanding that ozone is very thinly dispersed throughout the stratosphere. While there are traces of ozone at lower altitudes in the troposphere, the beneficial ozone layer that is often referred to is located much higher in the atmosphere. This layer is not "concentrated" over urban areas, nor is it found exclusively in the mesosphere or thermosphere, making the other options less accurate in their descriptions of ozone distribution.