Radiation belts occur

Options

A. In the exosphere
B. In thermosphere
C. Outside the exosphere
D. Between thermosphere and exosphere.

Answer

To solve the question regarding where radiation belts occur, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Radiation Belts**: Radiation belts, also known as Van Allen radiation belts, are zones of charged particles that are trapped by Earth's magnetic field. They are primarily located in the upper atmosphere.

2. **Identifying the Atmosphere Layers**: The Earth's atmosphere consists of several layers, including the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer has distinct characteristics.

3. **Locating the Radiation Belts**: The radiation belts are found at altitudes ranging from approximately 8400 miles (about 13,500 kilometers) to 36,000 miles (about 58,000 kilometers) above the Earth's surface.

4. **Evaluating the Options**:
- **Option 1: In the exosphere** - This is incorrect because the radiation belts are located outside the exosphere.
- **Option 2: In the thermosphere** - This is also incorrect as the radiation belts are not confined to the thermosphere.
- **Option 3: Outside the exosphere** - This is correct since the radiation belts are located beyond the exosphere.
- **Option 4: Between thermosphere and exosphere** - This is incorrect because the radiation belts are not situated in this region.

5. **Conclusion**: Based on the evaluations, the correct answer is that radiation belts occur outside the exosphere.

### Final Answer:
**Radiation belts occur outside the exosphere.**

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