Green house gas is _______.

Options

A. Nitrogen
B. Oxygen
C. Methane
D. Carbon dioxide

Explanation

**Step-by-Step Solution:**

1. **Understanding Greenhouse Gases**: Greenhouse gases are those gases in the Earth's atmosphere that trap heat. They allow sunlight to enter the atmosphere but prevent some of the heat that the sunlight brings from leaving the atmosphere. This process is known as the greenhouse effect.

2. **Identifying Common Greenhouse Gases**: The most common greenhouse gases include:
- Carbon Dioxide (CO2)
- Methane (CH4)
- Nitrous Oxide (N2O)
- Chlorofluorocarbons (CFCs)

3. **Analyzing the Options**: The question provides four options: Nitrogen, Oxygen, Methane, and Carbon Dioxide. We need to identify which of these is a greenhouse gas.

4. **Evaluating Each Option**:
- **Nitrogen**: While it makes up a large part of the atmosphere, it is not a greenhouse gas.
- **Oxygen**: Similar to nitrogen, oxygen is essential for life but does not contribute to the greenhouse effect.
- **Methane**: This is indeed a greenhouse gas, but it is not the most significant one.
- **Carbon Dioxide**: This is one of the primary greenhouse gases and is the most significant in terms of its impact on climate change.

5. **Conclusion**: Based on the analysis, the correct answer to the question "Greenhouse gas is _______" is **Carbon Dioxide**.

**Final Answer**: Greenhouse gas is **Carbon Dioxide**.

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