Which of the following gases are the contributor to the greenhouse effect?
I.Carbon dioxide
II.Methane gas
III.Nitrous oxide
Oxygen

Options

A. I,II III
B. II,III,IV
C. I,III,IV
D. I,II,III

Answer

To determine which gases contribute to the greenhouse effect, we can analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding the Greenhouse Effect**:
- The greenhouse effect is a natural process that warms the Earth's surface. It occurs when the Sun's energy reaches the Earth and some of it is reflected back to space and the rest is absorbed, warming the planet. Certain gases in the atmosphere trap this heat, preventing it from escaping.

2. **Identifying Greenhouse Gases**:
- The primary greenhouse gases include:
- **Carbon Dioxide (CO2)**: A major contributor to the greenhouse effect, primarily produced by burning fossil fuels and deforestation.
- **Methane (CH4)**: Another significant greenhouse gas, released during the production and transport of coal, oil, and natural gas, as well as from livestock and other agricultural practices.
- **Nitrous Oxide (N2O)**: Emitted from agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste.
- **Oxygen (O2)**: While essential for life, it does not contribute to the greenhouse effect.

3. **Evaluating the Options**:
- I. **Carbon Dioxide**: Yes, it contributes to the greenhouse effect.
- II. **Methane Gas**: Yes, it also contributes to the greenhouse effect.
- III. **Nitrous Oxide**: Yes, it is a contributor to the greenhouse effect.
- IV. **Oxygen**: No, it does not contribute to the greenhouse effect.

4. **Conclusion**:
- The gases that contribute to the greenhouse effect are Carbon Dioxide, Methane, and Nitrous Oxide. Therefore, the correct answer is options I, II, and III.

### Final Answer:
The gases that contribute to the greenhouse effect are:
- I. Carbon Dioxide
- II. Methane Gas
- III. Nitrous Oxide

Thus, the correct answer is **1, 2, and 3**.

---