Question

what do all mass movements have in common? a. moving water carries rocks, soil, or sediments down a slope. b. the removal of plants triggers soil to erode by wind, water, or gravity. c. an earthquake triggers rocks to shift and fall. d. gravity acts to pull rocks or soil down a slope.

Explanation:

Mass movements (like landslides, rockfalls, etc.) are defined as the downslope movement of rock, soil, or sediment due to gravity. Option A describes water - related transport (more like erosion/transport by water, not all mass movements). Option B describes erosion triggered by plant removal (not the core of all mass movements). Option C describes earthquake - triggered movement (earthquakes are a trigger for some mass movements, not a universal factor). Option D correctly states that gravity acts to pull rocks or soil down a slope, which is the fundamental force behind all mass movements.

Answer:

D. Gravity acts to pull rocks or soil down a slope.