Answer: Superposition
Step-by-step explanation:
The law of superposition is the term which is used to refers to the fundamental concept of the given sedimentary rocks of unreformed sequence.
This concept is basically explained about the sedimentary geology and also the different types of relative ages of the each bed in the given sedimentary rock sequence.
According to the given question, the given above statement is explained about the law of superposition that the each bed in the rocks is older as compared to the above layer and also younger than the given below layer.
Therefore, Superposition is the correct answer.