Which of the following is a greenhouse gas ?

Options

A. `SO_(2)`
B. `H_(2)S`
C. `CO_(2)`
D. `O_(2)`

Explanation

To determine which of the following is a greenhouse gas, we can follow these steps:

### Step 1: Understand what greenhouse gases are
Greenhouse gases are substances in the atmosphere that can trap heat. They allow sunlight to enter the atmosphere but prevent some of the heat that the sunlight brings from leaving the atmosphere. This leads to the greenhouse effect, which contributes to global warming.

### Step 2: Identify common greenhouse gases
Some of the most common greenhouse gases include:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Hydrofluorocarbons (HFCs)
- Water vapor (H2O)

### Step 3: Analyze the options given
In the question, we need to identify which of the listed substances is a greenhouse gas. The options provided include:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrogen dioxide (NO2)
- Sulfur tetrafluoride (SF4)
- Nitrous oxide (N2O)

### Step 4: Evaluate each option
- **Carbon dioxide (CO2)**: Known greenhouse gas.
- **Methane (CH4)**: Also a known greenhouse gas.
- **Nitrogen dioxide (NO2)**: Not primarily considered a greenhouse gas; it is more of an air pollutant.
- **Sulfur tetrafluoride (SF4)**: Not a significant greenhouse gas.
- **Nitrous oxide (N2O)**: A known greenhouse gas.

### Step 5: Conclusion
From the evaluation, we can conclude that the greenhouse gases among the options provided are:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)

However, if the question asks for only one correct option, then **Carbon dioxide (CO2)** is the most commonly recognized greenhouse gas.

### Final Answer:
**Carbon dioxide (CO2)** is a greenhouse gas.

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