Final answer:
The theory of plate tectonics explains that the Earth's lithosphere consists of several discrete segments known as tectonic plates, which move over the asthenosphere, shaping Earth's geological features.
Step-by-step explanation:
According to the theory of plate tectonics, the correct statement is that the Earth's lithosphere consists of several discrete segments. This theory explains the structure of the Earth's crust and many of the associated geological phenomena. It states that the Earth's lithosphere is broken into tectonic plates that move over the underlying asthenosphere due to mantle convection.
This movement of plates causes continental drift, mountain building, and volcanic activity, among other geological processes. It is incorrect to say that the positions of Earth's continents have remained the same, that plates have no significant effect on geology, that the lithosphere cannot move over the asthenosphere, or that the Earth is expanding over time. In fact, the movement of these tectonic plates has been responsible for the dynamic nature of Earth's geology, redirecting continents, and shaping the Earth's surface throughout its history.