Select the correct statement from the following.

Options

A. Global warming is caused by increased concentration of ozone.
B. Smog is formed from smoke and fog in the stratosphere layer.
C. Loam soil is a mixture of clay, silt and sand.
D. The non-living components of earth are called biotic components.

Explanation

To solve the question of selecting the correct statement regarding global warming and related concepts, we will analyze the statements one by one.

### Step-by-Step Solution:

1. **Understanding Global Warming**:
- Global warming refers to the increase in Earth's average surface temperature due to rising levels of greenhouse gases in the atmosphere.

**Hint**: Remember that greenhouse gases like CO2 and methane trap heat in the atmosphere.

2. **Evaluating the First Statement**:
- The first statement claims that global warming is caused by the increased concentration of ozone.
- Ozone (O3) is a greenhouse gas but is primarily located in the stratosphere, where it protects us from harmful UV radiation. While ozone can contribute to warming in the troposphere, it is not the primary cause of global warming.

**Hint**: Consider the main greenhouse gases responsible for global warming, such as carbon dioxide and methane.

3. **Evaluating the Second Statement**:
- The second statement suggests that smoke is formed from smoke and fog and the stratosphere layer.
- This statement is unclear and seems to mix concepts. Smoke is a mixture of gases and particulate matter resulting from combustion, while fog is a collection of tiny water droplets. The stratosphere is a layer of the atmosphere above the troposphere, and it does not directly relate to the formation of smoke.

**Hint**: Think about the definitions of smoke, fog, and the layers of the atmosphere.

4. **Conclusion**:
- After evaluating both statements, neither accurately describes the causes of global warming or the formation of smoke and fog.
- Therefore, if these are the only statements provided, we conclude that neither is correct.

### Final Answer:
Neither statement is correct regarding global warming and the formation of smoke and fog.