Which statement reflects the principle of relative dating?

• A. The exact age using isotopes
• B. The method relies on fossil succession to date rocks
• C. The method uses layer positions to determine order
• D. The rock layers on the bottom are older than the ones deposited above

Answer: (D)

The main idea is ordering rocks by their position to determine which are older or younger, a principle called the Law of Superposition. In an undisturbed sequence of sedimentary layers, the oldest material settles first at the bottom, and each new layer forms on top of older ones. So saying that the bottom rock layers are older than the layers deposited above captures this ordering directly: you can compare their relative ages just from their positions without needing a numeric age. This is what relative dating uses. Radiometric dating with isotopes gives exact ages (numbers), which is why that option isn’t the best fit here. Fossil succession helps correlate and infer ages but doesn’t state the straightforward bottom-to-top age relationship as clearly as this principle.