20 ! 11 what happens in a landslide? a. earth materials that are no longer held by friction move down a slope. b. water moves into an area where it does not belong. c. soil washes away into a stream. d. the upper region of a hill becomes built up by rocks.

Answer A seems to be the most proper answer to the question. Since a landslide is something getting loose from a mountain or cliff, it is held by friction. Rocks, large pieces of dirt and other objects are help on to steep mountains by friction. 
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The cliffs become over saturated with water allowing it to go down the mountain, causing catastrophic damage

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