Answer:
C. Faults are younger than the youngest layer they cut through.
Explanation:
A. Intrusive rock is older than the surrounding rock layers. WRONG. The intrusive rocks are those that solidify underground and always form after the ones around them. So they are younger than the surrounding rocks.
B. A fold is older than the oldest rock layer it contains. WRONG. First, layers are set, and then, it occurs the folding. The folding is always younger than the involved layers.
C. Faults are younger than the youngest layer they cut through. RIGHT. A fault is a cut through different layers that occurs when the sedimentary rock breaks transversally. It occurs always after the sedimentary rock is already formed. So the fault is always younger than all the layers it cuts through.
D. Rock layers that have been overturned are oldest from the base to the surface. WRONG. If overturned, according to the superposition low, layers are oldest from the surface to the base. Superposition law states that during the sedimentary rock formation, the oldest layer is always that one at the bottom, while the younger layer is the higher one.
