Which statement best explains the theory of plate tectonics?
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Earth’s crust is composed of rock plates that float on top of the mantle.
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Earth’s crust is formed by the magma that rises in the mantle.
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Earth’s core consists of rock plates that float on top of the mantle.
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Earth’s mantle is made of rock plates that move across the crust.
The correct answer is: Earth’s crust is composed of rock plates that float on top of the mantle.
Explanation: The theory of plate tectonics states that the Earth's crust is divided into several large and small plates that are in constant motion. These plates, also known as lithospheric plates, are made up of solid rock and float on the semi-fluid layer of the Earth's mantle. The movement of these plates is driven by the convective flow of the underlying mantle material. As the plates move, they interact with each other at their boundaries, resulting in various geological phenomena such as earthquakes, volcanic activity, and the formation of mountain ranges.