Why Does the Beach Slope Under Water Become Steeper near Shore

Why does the beach slope under water become steeper near shore?

A) The sand grains are finer near shore.
B) The bottom has to rise rapidly to merge with the sand of the barrier island.
C) Sand from the onshore part of the beach has to drop abruptly because offshore the sand is under water.
D) Waves in shallow water drag on the bottom, so they lose energy and need a steeper slope to move the sand.
E) The waves are bigger near shore.