Answer:
Relative dating is the technique to calculate the age of an ancient materials in comparison to another material's age. Layer A is less older, if layer B lies beneath it. Layer A may be 2.5 to 3 million years old.
Step-by-step explanation:
Before discovery of radioactive carbon dating method, geologists make use of relative dating method in order to determine the age of rock or fossils. The relative dating procedure often referred to as stratigraphy. Though this procedure is not capable of predict absolute age or dating. In relative dating, is mainly based on the fact that the older rock layers will be deeper in respect to the less older rock layer.