Which statement accurately describes Earth's basic structure and mantle division?

• A. The lithosphere, asthenosphere, and core
• B. The crust, mantle, and core
• C. The atmosphere, hydrosphere, and geosphere
• D. The magnetosphere and crust

Answer: (B)

Earth's basic structure is described by three main chemical layers: the crust, mantle, and core. The crust is the thin outer shell, with continental and oceanic types. Beneath it sits the mantle, a thick middle layer that extends down to the outer core; it’s commonly discussed in terms of upper and lower mantle, with the lithosphere as the rigid outer part of the mantle and crust together, and the asthenosphere as the softer layer beneath it. The core lies at the center and includes a liquid outer core and a solid inner core, driving Earth’s magnetic field.

This makes the statement about crust, mantle, and core the best description of Earth's basic internal structure and its mantle division. The other options mix in concepts that aren’t the primary internal divisions: lithosphere and asthenosphere are mechanical zones within the upper mantle, not the fundamental chemical layers; atmosphere, hydrosphere, and geosphere refer to Earth’s systems rather than its interior; and magnetosphere is a region related to magnetic field, not a structural layer inside Earth.