The correct option is B Mangrove forests
Mangroves are salt-tolerant plants of tropical and subtropical intertidal regions of the world. The specific regions where these plants occur are termed as 'mangrove ecosystem'. These are highly productive but extremely sensitive and fragile. Besides mangroves, the ecosystem also harbours other trees like Hetal, Dhundal and Sundari trees. Sunderban, the world's largest estuarine forest and delta covered by mangrove forests is characterized by the Sundari trees that give the mangrove their name.