Question

How are seawalls used to control coastal erosion?

Seawalls reduce the energy of destructive waves and wave pounding.

Seawalls increase the energy of destructive waves and reduce wave pounding.

Seawalls break up the waves offshore and change their direction, reducing their energy.

Seawalls are not used to control coastal erosion but do prevent longshore drift from occurring.

Answer 1

If I'm thinking right then Seawalls reduce the energy of destructive waves pounding because the power of waves break up the coast and help erode it with the pounding.