The region closest to earth's surface is :

Options

A. stratosphere
B. mesosphere
C. troposphere
D. thermosphere.

Answer

To determine the region closest to Earth's surface, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Layers of the Atmosphere**: The Earth's atmosphere is divided into several layers based on altitude. These layers include:
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere

2. **Understand the Order of the Layers**: The layers are arranged in order from the Earth's surface upwards:
- **Troposphere**: This is the lowest layer and is where we live. It contains most of the atmosphere's mass and is where weather occurs.
- **Stratosphere**: Located above the troposphere, it contains the ozone layer.
- **Mesosphere**: Above the stratosphere, this layer is where meteors burn up upon entering the atmosphere.
- **Thermosphere**: This layer is characterized by high temperatures and is where the auroras occur.
- **Exosphere**: The outermost layer, where the atmosphere thins out and merges into space.

3. **Determine the Closest Layer**: Since the question asks for the region closest to the Earth's surface, we identify that the troposphere is the first layer above the Earth's surface.

4. **Conclusion**: Therefore, the region closest to the Earth's surface is the **Troposphere**.

### Final Answer:
The region closest to Earth's surface is the **Troposphere**.

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