Aseawall is protecting the coastline from what? a. earthquakes b. mudslides c. wave action d. tidal surge

A seawall is protecting the coastline from C. Wave action.

Wave action is the continuous process in the ocean that brings up the sand to the coastal areas. These waves have the huge amount of energy stored in it.

So, the sea wall is constructed in the coastal areas to act as a defensive compound to decrease the force and energy of the waves. It helps in reducing erosion and the damage of floods in the coast line areas.