The Earth's inner core reaches temperatures that are at times greater than 9000°F. What causes this layer to remain solid despite the high temperature?

D. the immense pressure that it is under

Explanation:

The Inner Core is made up of iron and experiments have shown that when the pressure on a solid such as Iron increases, so does it's melting point. The Earth's inner core is under a lot of pressure from the Mantle as well as the outer core.

This pressure increases the melting point of the iron to a point where it is higher than the temperatures in it which causes it to remain in a frozen state.

the answer is a. 250 percent.