Final answer:
The theory of plate tectonics describes the movement of Earth's lithosphere.
Step-by-step explanation:
The correct answer is the movement of Earth's lithosphere. The theory of plate tectonics is a widely accepted scientific theory that explains how the Earth's lithosphere, which is made up of several large and small tectonic plates, moves and interacts with each other. These plates float on the semi-fluid asthenosphere beneath them. Plate boundaries are where most of the geological activities and phenomena occur, such as earthquakes, volcanic eruptions, and the formation of mountains.
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