Which of the following can serve as a reliable safety hedge against coastal calamities?

Mangroves form a reliable natural safety hedge, their dense roots absorbing wave energy and shielding coasts from storms and surges.

Coral reefs do break waves offshore but are more fragile and bleach easily, making them a less dependable shield here.

The pairing of both is not the intended answer since mangroves are the singled-out reliable hedge.

Saying none of these works ignores the well-proven protective value of coastal mangrove belts.

Mangrove forests also trap sediment, stabilise shorelines and reduce erosion.

They buffered many villages during the 2004 Indian Ocean tsunami.