Explanation:
The lithosphere is the sphere of the land on Earth. It comprises the Earth's crust and the uppermost part of the mantle, forming the solid, outer layer of the planet. The lithosphere is divided into tectonic plates, which float on the semi-fluid asthenosphere beneath them. This layer includes all the landforms, such as mountains, valleys, and plains, and is crucial for supporting terrestrial life. The other terms, stratosphere and mesosphere, refer to layers of the Earth's atmosphere, not the land. Understanding the lithosphere helps in studying geology, tectonics, and Earth's physical features.