Answer: The correct answer is option C, the principle of superposition.
Step-by-step explanation:
In geology, the principle of superposition states that in a series of stratified sedimentary rocks, the one that sits at the bottom ( the lowest stratum) is the oldest.
According to the details given above, the geologist observed that sandstone sits on top of the granite(the granite sits at the bottom), he concluded that granite is older than the sandstones. This principle clearly demonstrates the theory of superposition.
Superposition simply means putting something on top of another (for example, placing an object on top of another object).
Therefore, the above principle describes the theory of superposition.