Which statement best explains the theory of plate tectonics?

1.Earth's crust is formed by the magma that rises in the mantle.
2.Earth's mantle is made of rock plates that move across the crust.
3.Earth's core consists of rock plates that float on top of the mantle.
4.Earth's crust is composed of rock plates that float on top of the mantle.

1 answer

The statement that best explains the theory of plate tectonics is:

4. Earth's crust is composed of rock plates that float on top of the mantle.

This accurately describes the concept that the Earth's lithosphere (which includes the crust) is divided into tectonic plates that move and interact with each other on the more fluid asthenosphere beneath.