Final answer:
Moving downward from the Earth's mantle to the core, both density and temperature increase due to compression and high core material density.
Step-by-step explanation:
As we move downward into the Earth, from the mantle to the core, we can expect certain changes in both density and temperature. The mantle is composed of rock that can deform and flow slowly, with density increasing from about 3.5 g/cm³ to more than 5 g/cm³ towards its base due to compression from the overlying material.
The core of the Earth, which starts at a depth of 2900 kilometers, is much denser and hotter with its outer layer being liquid and the inner core being solid. The core is composed primarily of iron, nickel, and sulfur, all highly compressed to a very high density. Therefore, as we go deeper into the Earth, we see that both the density and temperature increase, which corresponds to option B of the provided choices.