what is an earthquake, and how do earthquakes generally (most commonly) occur? a. a sudden shaking of the ground that is caused by the rapid movement of one block of rock past another block of rock at a fault b. a sudden shaking of the ground that is caused by meteor impacts c. a sudden shaking of the ground that is caused directly by convection within the mantle d. a sudden shaking of the ground that is caused by volcanoes erupting e. a sudden shaking of the ground that is caused by the impacts of falling rocks