In a slump, - sediment and rock fall off a slope in concave curves - rock fragments slide down a pre existing surface - water, mud, and rock fragments rush down an incline - rocks and sediment fall at high speeds from high elevation

The correct answer is option a, that is, the sediment and rock fall off a slope in concave curves.

A slump refers to a kind of mass wasting, which takes place when a coherent mass of loosely consolidated layers of rock or materials moves a short distance down a slope. The movement is featured by sliding along a concave-upward or planar surface.

The reasons for slumping involve freezing and thawing, earthquake shocks, thorough wetting, undercutting, or loading of a slope.

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.