Concept:Coastal landforms can be grouped by the process that creates them, either erosion or deposition.Explanation:A bay forms where softer rock is worn away faster than the surrounding harder rock.A cliff is produced when wave action cuts into and undercuts the land.An arch develops when erosion breaks through a headland or rocky projection.A beach is built up by the deposition of sand, shingle, and pebbles carried by waves.Therefore, a beach is not a product of erosion.Answer:C. Beach