Answer: the answer is C ,
A massive landslide Mud flows in the Toutle river
Explanation:
There had been many earthquakes in the area prior to eruption but this happen to be a massive land slide because a moving magma have over steepened the mountain slopes..this geologic process uses gravity to cause rock, soil, artificial fill or a combination of the three to move down a slope. Slow weathering of rocks as well as soil eruption and volcanic activity also causes landslides