Here's why:
* Lithosphere: This is the rigid outermost layer of the Earth, composed of the crust and the uppermost part of the mantle. It's broken into tectonic plates that move and interact, causing mountain formation (through collisions) and ocean trenches (through subduction).
* Other layers: The asthenosphere (below the lithosphere) is mostly solid but behaves like a viscous fluid, allowing the tectonic plates to move. The mesosphere, outer core, and inner core are all deeper layers that don't directly impact the formation of mountains and oceans.
