The harmful Ozone is present in

Options

A. Troposphere
B. Stratosphere
C. Mesosphere
D. Thermosphere

Answer

### Step-by-Step Solution:

1. **Understanding Ozone**:
- Ozone (O₃) exists in two main layers of the atmosphere: the stratosphere and the troposphere.
- It is important to differentiate between "good ozone" and "bad ozone".

2. **Good Ozone**:
- Good ozone is found in the stratosphere.
- It plays a crucial role in absorbing harmful ultraviolet (UV) radiation from the sun, thus protecting living organisms on Earth.

3. **Bad Ozone**:
- Bad ozone, or harmful ozone, is found in the troposphere.
- It is not naturally occurring; rather, it is formed from chemical pollutants and is considered a secondary pollutant.
- This type of ozone is harmful to human health and the environment.

4. **Analyzing the Options**:
- **Option A: Troposphere** - This is where harmful ozone is found. It is the correct answer.
- **Option B: Stratosphere** - This contains good ozone, which protects against UV rays. Incorrect.
- **Option C: Mesosphere** - This layer does not contain significant amounts of ozone and is not relevant to the question. Incorrect.
- **Option D: Thermosphere** - This is the outermost layer of the atmosphere and is also not related to ozone. Incorrect.

5. **Conclusion**:
- The harmful ozone is present in the troposphere. Therefore, the correct answer is **Option A: Troposphere**.