How is plate tectonics defined?

Plate tectonics is accurately defined as a scientific theory explaining the movement of Earth's plates and geological activity. This theory provides a comprehensive framework for understanding how the Earth's lithosphere, which is divided into several large and small tectonic plates, interacts with one another. The movements of these plates can lead to a variety of geological phenomena, including earthquakes, volcanic eruptions, mountain-building, and the creation of ocean basins.

The core concepts of plate tectonics include the idea that these tectonic plates float on the semi-fluid asthenosphere beneath them, and their interactions are driven by forces such as mantle convection, slab pull, and ridge push. Understanding plate tectonics is essential for explaining not only the structure of the Earth's surface but also the distribution of various geological features and the processes that shape the planet over geological time.

The other options do not relate to the specific framework and the scope of plate tectonics. For instance, celestial body movements and ocean currents, while scientific topics, do not encompass the geological processes described by plate tectonics, nor do they address the interactions between tectonic plates. Similarly, hypotheses regarding the formation of the sun and moon fall outside the domain of Earth's geology and plate tectonics.