What term denotes the outermost cool rigid layer consisting of crust and upper mantle?

What term denotes the outermost cool rigid layer consisting of crust and upper mantle?

• A. Mantle
• B. Crust
• C. Lithosphere
• D. Core

Answer: (C)

The outermost cool, rigid shell of Earth that includes both the crust and the rigid portion of the upper mantle is the lithosphere. This layer behaves as a solid, rigid shell and forms the tectonic plates that move atop the softer, more ductile mantle beneath. The mantle by itself refers to the entire layer beneath the crust, not including the crust, while the crust alone is only the outermost shell without the upper mantle portion. The core is the central part of the planet, far below the mantle. So, when the description specifies a cool, rigid outer layer made up of crust and upper mantle, lithosphere is the best fit.

The outermost cool, rigid shell of Earth that includes both the crust and the rigid portion of the upper mantle is the lithosphere. This layer behaves as a solid, rigid shell and forms the tectonic plates that move atop the softer, more ductile mantle beneath. The mantle by itself refers to the entire layer beneath the crust, not including the crust, while the crust alone is only the outermost shell without the upper mantle portion. The core is the central part of the planet, far below the mantle. So, when the description specifies a cool, rigid outer layer made up of crust and upper mantle, lithosphere is the best fit.