Which statement describes the law of superposition?

Sedimentary rocks were originally in horizontal layers.

In horizontal rock layers, each layer is younger than the one below it.

Rock layers must be in existence before something can happen to them.

Rocks that are not in horizontal layers were shifted by some geologic event.

Option (B)

Explanation:

The law of Superposition was first introduced by Nicolas Steno in 17th century. This law says that in an undisturbed sedimentary rock layers or sequence, the rocks that are found at its base are the oldest rocks and the rocks that are found at the apex indicates the youngest rocks.

In nature, all sedimentary sequences do not satisfy this principle, because sometimes, some sedimentary sequences are affected by several factors such as the plate tectonic activity, earthquake, and faulting.

Thus, the rock layers that are present above are younger than the one that is below it.

Hence, the correct answer is option (B).

In horizontal rock layers each layer is younger than the one below it