Why Would a Slope Be More Prone to Slumping After

Why would a slope be more prone to slumping after storm A (ten successive days of 1/3-inch of rain every day) in comparison to storm B (a five-hour storm that totals 6 inches of rainfall) ?

A) In storm A, much of the water is likely to run off and not percolate into the slope.
B) In storm A, the rainfall is slow and steady enough for nearly all of it to percolate into the slope.
C) In storm B, debris flows might occur rather than slumps.
D) All of the above are correct.