What effect does wave action typically have on the materials at the seabed?

Wave action is a dynamic force that plays a significant role in shaping coastal environments and the materials found at the seabed. When waves break against the shore, they exert significant energy on sediments, rocks, and other materials. This energy can cause the disintegration and erosion of larger rocks and sediments, consequently leading to the formation of smaller particles such as sand. Over time, the relentless pounding of waves gradually breaks down materials, allowing them to be transported and deposited in other areas, contributing to the creation of sandy beaches and coastal landforms.

In contrast, while wave action can change the shape of materials on the seabed, such as rounding off sharp edges, the primary effect in terms of coastal sediment is the production and accumulation of sand as a result of this erosion and transportation process. Therefore, the option that states wave action creates sand accurately reflects the main geological and sedimentary impact of waves on seabed materials.