Which coastal feature forms when winds blow sand inward to create the primary shoreline protection?

• A. Dunes
• B. Barrier Flat
• C. High Salt Marsh
• D. Lagoons

Answer: (A)

Shoreline dunes form when wind lifts and moves sand from the beach and deposits it inland, building ridges that run parallel to the shore. These ridges act as the first line of defense, absorbing and dispersing wave energy and reducing erosion for the land behind them. The wind-driven transport—sand moving by saltation and creep—creates and enlarges these mounded features, and vegetation often helps stabilize them so they persist as a protective barrier. The other options don’t fit this wind-driven buildup: barrier flats are flat areas behind barriers, high salt marshes develop in waterlogged, saline soils, and lagoons are shallow water bodies formed by tidal and hydrological processes behind barriers, not by inward-moving sand forming a protective ridge. So the feature formed by winds blowing sand inward to create the primary shoreline protection is dunes.