The correct option is Stratosphere.
Explanation
The atmosphere consists of concentric layers of air with varying density and temperature. The ozone layer, which protects the Earth from harmful ultraviolet (UV) radiation, is primarily situated within the stratosphere. The term "Ozone Hole" specifically refers to the significant thinning of this layer.
Detailed Analysis
- Stratosphere: This layer extends from the top of the troposphere (around 10-18 km) to about 50 km above the Earth's surface. The ozone layer is concentrated in the lower portion of the stratosphere (approximately 15 to 35 km). The "Ozone Hole" is a periodic depletion of this stratospheric ozone, most notably observed over Antarctica.
- Troposphere: This is the lowest layer where weather phenomena occur. While it contains some ozone (ground-level ozone), this is considered a pollutant and a greenhouse gas, distinct from the protective stratospheric ozone.
- Mesosphere and Thermosphere: These layers lie above the stratosphere. They do not contain significant concentrations of ozone relevant to the "Ozone Hole" phenomenon.
Key Takeaway: The "Ozone Hole" represents a depletion of the protective ozone layer located in the stratosphere, which is essential for absorbing the Sun's harmful ultraviolet radiation.