Which statement best describes the theory of plate tectonics? A. Plates sometimes move closer to one another.

B. Sections of Earth that shift are part of Earth's asthenosphere.

C. Sections of Earth's continents are in slow, constant movement.

C. Parts of the ocean floor move as they are carried by rift valleys,

Sections of Earth's continents are in slow, constant movement.

Explanation:

Earth's crust is broken up and divided into numerous pieces. These pieces are called tectonic plates and they come in various shapes and sizes. The tectonic plates can consist predominantly of continental crust or predominantly of oceanic crust, and there isn't a single plate that is exclusively made out just from one type of crust.

The reason why Earth's crust is broken apart is the force that comes from the convection currents from the mantle below it. Not just that the convection currents break up the crust, but they also push it in a certain direction. By doing so, the convection currents manage to move the tectonic plates on Earth's surface, and even though this is a slow movement, it has huge effects.