What Adverse Effect Do Groins and Jetties Both Have on Coastal

Multiple Choice

What adverse effect do groins and jetties both have on coastal erosion?

A) They stop littoral transport of sand and starve down-drift areas of sand.
B) They reflect waves across the beach.
C) They cause the waves striking the structure to increase in height and erosive power.
D) They rob the waves of their energy to transport sand.