The gaseous envelope around the earth is known as atmosphere. The lowest layer of this is extended upto `10` km from sea level , this layer is

Options

A. stratosphere
B. troposphere
C. mesophere
D. hydrosphere

Explanation

To answer the question regarding the lowest layer of the Earth's atmosphere that extends up to 10 km from sea level, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Atmosphere**: The atmosphere is the gaseous envelope surrounding the Earth. It is divided into several layers based on temperature and altitude.

2. **Identifying the Layers of the Atmosphere**:
- **Troposphere**: This is the lowest layer of the atmosphere. It extends from the Earth's surface up to about 10 km. It is where weather phenomena occur and contains most of the atmosphere's mass, including water vapor.
- **Stratosphere**: This layer starts above the troposphere and extends from about 10 km to 50 km. It contains the ozone layer, which absorbs and scatters ultraviolet solar radiation.
- **Mesosphere**: This layer is above the stratosphere, extending from 50 km to about 85 km.
- **Thermosphere**: This layer extends from about 85 km to 600 km and is characterized by a significant increase in temperature with altitude.
- **Exosphere**: This is the outermost layer of the atmosphere, extending from about 600 km to 10,000 km.

3. **Determining the Correct Layer**: Since the question specifies the layer that extends up to 10 km from sea level, we conclude that the correct answer is the **Troposphere**.

4. **Final Answer**: The lowest layer of the atmosphere that extends up to 10 km from sea level is the **Troposphere**.