Answer:
The correct answer is option A. core.
Explanation:
The core is the innermost layer of the earth. It is a very hot, dense center of the earth that is beneath the solid mantle and crust that are cold. It is a solid ball that has about a 3485-kilometer radius.
The core of the earth is very hot regions which are said to be because of radioactive decay of different elements.
Thus, the correct answer is option A.
