Which of the following best describes the lithosphere?

The lithosphere is best described as the outer crust of the Earth. This layer is composed of the rigid, rocky portion that includes both the continental and oceanic crust. It features a solid structure, which extends to a depth of about 100 kilometers (62 miles) and is a crucial component of tectonic activity, providing a foundation for the atmosphere and hydrosphere, as well as containing the minerals and materials essential for life.

Other options refer to different layers or aspects of the Earth. The liquid part of the Earth is associated with the mantle and outer core, which are not considered part of the lithosphere. The gaseous envelope surrounding the Earth is referred to as the atmosphere, while the biosphere pertains to regions where life exists, encompassing areas of the lithosphere, hydrosphere, and atmosphere. Thus, the description of the lithosphere as the outer crust most accurately reflects its characteristics and importance in Earth's structure.