The correct option is An off-shore bar exposed due to further addition of sand..
Explanation
Coastal landforms are primarily classified into erosional and depositional features. Depositional landforms are created when sediments like sand, gravel, and silt are deposited by waves and currents along the shore. Bars, barriers, and spits are key examples of such features.
Detailed Analysis
- An off-shore bar exposed due to further addition of sand. is Correct: An off-shore bar is a ridge of sand and shingle formed in the sea in the off-shore zone, lying approximately parallel to the coast. When this off-shore bar accumulates enough sediment to rise above the water level and becomes exposed, it is termed a barrier bar.
- A ridge of sand formed on the beach by wind. is Incorrect: A ridge of sand formed on the beach primarily by wind action is known as a sand dune. While dunes are often associated with coastal environments, they are aeolian (wind-driven) features rather than direct wave deposition forms like barrier bars.
- A rock remnant standing in the sea. is Incorrect: A rock remnant standing in the sea, isolated from the coast due to wave erosion, is called a sea stack. This is an erosional landform, not a depositional one.
- A depression filled with water behind a spit. is Incorrect: The depression filled with water enclosed behind a barrier bar or spit is called a lagoon. The barrier bar is the physical ridge, while the lagoon is the water body it isolates from the open sea.
Key Takeaway: A barrier bar is essentially an off-shore bar that has been built up by wave deposition until it is exposed above the water surface, often forming a chain of islands parallel to the coast.