Approximately what percentage of available ozone is found in the stratosphere layer?

The correct answer is that approximately 90% of the available ozone is found in the stratosphere layer. The stratosphere is the second major layer of Earth's atmosphere, situated above the troposphere and below the mesosphere.

Ozone is primarily concentrated in the stratosphere and forms the ozone layer, which plays a crucial role in protecting life on Earth by absorbing the majority of the sun's harmful ultraviolet (UV) radiation. This absorption of UV radiation helps to prevent skin cancers, cataracts, and other negative health effects in humans, as well as protecting ecosystems and wildlife.

While there is ozone present at different altitudes in the atmosphere, the vast majority resides in the stratosphere. The other options represent significantly lower percentages of ozone concentration, which do not accurately reflect the reality of where most of the ozone is located. This high concentration in the stratosphere is why it is often referenced when discussing ozone and its environmental importance.