If the crust cooled but internal heat remained, which conclusion is most accurate?

Correct answer: Earth’s surface and interior evolved at different rates

Option A is the most accurate conclusion because surface cooling and internal cooling do not necessarily occur at the same rate. The crust may become relatively rigid and cool at the surface while heat remains stored in the mantle and core. Continuing internal heat can sustain convection, magma generation, volcanism, earthquakes, and tectonic change, even when the external surface appears comparatively stable. Therefore Earth’s outer and inner parts may follow different developmental paths. Complete inactivity is contradicted by the remaining heat; there is no basis for saying oceans disappeared first; and ozone cannot create a metallic core. The answer recognises Earth as a layered, changing system.