Ans. Landforms are all due to the destruction and construction of rocks. Destructive forces are a result of usual wind and water erosion. However, constructive forces include volcanic eruption, deformation, and deposition of sediments. Since an arch ocean is caused due to water and wind erosion on the weaker rock section, it is a destructive landform. The falling of huge ocean waves on the weaker rocks day by day causes a hollow cavity. This open cavity is a passage from one side of the ocean to another in the gate-like structure we call an arch. These arches give rise to either a natural bridge and form an entrance into the sea to pass-by. It is a million or thousand years process occurring without human aid.