If a sandstone lies on top of a shale, a. their relative ages cannot be determined from the information given b. the shale must be older, according to the principle of components c. the shale must be older, according to the principle of superposition d. the sandstone must be older, according to the principle of superposition

The answer is the shale must be older, according to the principle of superposition
In physics, the princilpe of superposition means that the net response that is created by two or more stimulis is the total of the responses that would've been caused by each stimulus individually. So, when two objects burried with equal amount of force, the one that burried deepet can be conclude to be experiencing that force longer than the one that place on top of it.