Why Does Removing Driftwood from a Beach Endanger the Sea

Why does removing driftwood from a beach endanger the sea cliffs behind it?

A) Waves cannot get over the driftwood to get to the sea cliffs.
B) Waves have to be higher to reach over the driftwood to reach the sea cliffs.
C) Wave energy is reduced when waves move the driftwood.
D) Driftwood bouncing up and down on the beach pounds the sand grains together, making them more difficult to erode.
E) Driftwood breaks up the direct forward thrust of the waves, making them more erratic.