What Is "Grading" as It Pertains to the Stability of a Slope

Multiple Choice

What is "grading" as it pertains to the stability of a slope?

A) A classification of how likely a slope is to slide
B) The greatest slope that a material can be stable at
C) A classification of the material in the slope
D) Human-induced changes in the slope angle to make it more or less steep
E) A measure of the maximum weight a slope can hold