A geology professor creates a small-scale model of one of the principles of relative-age dating. The professor pours several layers of sand into a large container. Each layer is a different color. Students analyze the layers to identify which colors represent the oldest and the youngest layers.

What principle of relative-age dating is being modeled here, and how do we know?

O A) Superposition, because it deals with the order in which the layers are deposited

OB) Lateral continuity, because it describes how sediments deposit in layers

OC) Inclusions, because small particles like sand must have several inclusions

OD) Cross-cutting relationships, because the sand colors must mix across layers