Which statement best describes erosion in the context of rocks and water?

• A. It transports and wears down rocks, often by water or wind.
• B. It occurs only on land and never in water.
• C. It changes the chemical composition of rocks.
• D. It rapidly forms sedimentary rocks.

Answer: (A)

Erosion is the process of wearing away and moving rock or soil by natural forces such as water or wind. In rocks and water, this means running water or waves can pick up particles and transport them away, while at the same time wearing surfaces down. That dual idea—both transporting material and wearing it away—is why this description fits best.

Erosion isn’t primarily about changing the rock’s chemical makeup—that’s chemical weathering. It also isn’t about quickly forming rocks; sediments produced by erosion must first be deposited and then cemented or compacted over time to become sedimentary rocks. And erosion certainly can occur in water, not just on land, as seen in rivers carving valleys or coastlines weathering away shorelines.