The fatal La Conchita landslide, discussed in this week's video, started moving like a landslide or slump, but then it began to flow more fluidly downslope. The geologic investigation showed that water and weak sedimentary rock were major contributing factors. Which of the following describes how water was able to mobilize this flow exceptionally rapidly? Select one: a. Water percolated the weak sedimentary bedrock via fractures and joints b. Days of heavy rain saturated the landslide material so it flowed down slope like mud c. Groundwater in the landslide pooled up on a buried fault surface, which consisted of impermeable clay (i. e., fault gouge) and increased the pore pressure d. A recent wildfire in the area destabilized the topsoil and made the slope vulnerable to erosion. e. All of these