Which statement best summarizes how erosion rates depend on rock type, climate, and vegetation cover?

• A. Harder rocks erode slowly; warm, wet climates accelerate weathering; dense vegetation reduces erosion
• B. Softer rocks always erode more slowly
• C. Colder climates accelerate weathering more than warm, wet climates
• D. Vegetation increases erosion

Answer: (A)

Erosion rates reflect three main factors: how resistant the rock is, how climate drives weathering, and how vegetation protects the surface. Harder rocks resist breakdown and therefore erode more slowly than softer rocks under the same conditions. Warm, wet climates boost weathering (especially chemical weathering) and speed up erosion compared with cooler, drier conditions. Dense vegetation helps hold soil in place with roots, shields the surface from raindrop impact, and reduces runoff, all of which lessen erosion. The best summary ties these ideas together: harder rocks erode slowly; warm, wet climates accelerate weathering; dense vegetation reduces erosion. The other statements mix up these relationships: softer rocks don’t erode more slowly; cold climates don’t generally outpace warm, wet climates in driving weathering; and vegetation tends to protect against erosion rather than exacerbate it.