Correct Option: D

Sundarbans is the largest single block of tidal halophytic mangrove forest in the world. The Sunderbans is a UNESCO World Heritage Site covering parts of Bangladesh and India. This region is densely covered by mangrove forests, and is one of the largest reserves for the Bengal tiger. The Sundarbans is intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests. The mangrove-dominated Ganges Delta – the Sundarbans – is a complex ecosystem comprising one of the three largest single tracts of mangrove forests of the world. Situated mostly in Bangladesh, a small portion of it lies in India.