Which layer includes both the crust and the upper mantle as its components?

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

Answer: (A)

The main idea is recognizing a layer that combines the outermost chemical skin of Earth with the upper portion of the mantle. This layer, known as the lithosphere, is the rigid outer shell that includes both the crust and the upper mantle. It behaves as a brittle, solid shell and forms the tectonic plates that move on the deeper, more ductile layer beneath called the asthenosphere. The reason this is the best answer is that the lithosphere explicitly contains both the crust and the upper mantle as its components, whereas the mantle proper refers to the deep mantle alone, the crust refers only to the outermost skin, and the outer core lies far beneath these layers.