Description : Atoll is a kind of – (1) sand-dune (2) lake (3) sandbar (4) inland sea
Last Answer : (4) inland sea Explanation: Atoll is a coral island (or islands) that encircle a lagoon partially or completely. It is formed when the island sinks below the sea, and the barrier reef becomes ... sea which is a shallow sea that covers central areas of continents during periods of high sea level.