Riprap added to the base of a steep slope .A. absorbs wave energy and can slow the undercutting of coastal cliffs. B. can make the slope less stable. C. should be removed before it causes a rockfall. D. is a useful way to prevent avalanches.

Rip-rap called as rock shield is the man-made rock that is used as a shields to protect the shoreline, streambeds and bridges and the other structure against the water, waves, and ice erosion and the most common type includes granites and concrete.

Hence the option A is correct in that it absorbs the wave energy and can also slow the undercutting of the coastal cliffs.

Learn more about the Riprap to the base of the steep slope.

d. loss of habitat and farmland