Answer:
weathering and erosion
Step-by-step explanation:
Weathering and erosion are the main causes of the decrease in the height of Mount Mitchell, since these are the two main processes that result in dispersion and a decrease in the amount of land "mass". Weathering is the natural process of decomposition of the rock, while erosion is the process of removal of rocks or terrestrial material, which is lost due to wind, rain, among other factors.