The correct answer is B) law of superposition.
The law that states that rock layers closest to the surface are the youngest rock is the law of superposition.
One of the most important principles in Geology, the study of the rocks on planet Eart- is the Law of Superposition. It says that layers of rock that are at the very top are younger than the ones at the bottom. That is how geologists study the years of the rock and the era they belonged to. Other important geological laws studied by Geologists are the Law of Lateral Continuity and the Law of Original Horizontality.