Answer;
A. slippage of a block of material moving along a curved surface
Explanation;
-A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or rock layers moves a short distance down a slope. Movement is characterized by sliding along a concave-upward or planar surface.
-A slump often occurs when water soaks the base of an inclined mass of soil. Slump is a slower process, it happens over time. The difference between a creep and a slump is that a creep moves slowly and gradually while a slump is faster and causes more drastic changes in terrain. A slump is a downward and outward movement of rock, soil or other material.
