Which of the following National Parks is unique in being a swamp with floating vegetation that supports a rich biodiversity?

1. A

   Bhitarkanika National Park

   (a) Bhitarkanika National Park. This Odisha park is a mangrove and saltwater-crocodile landscape, not a floating-phumdi swamp. It is the wrong habitat type.

2. B

   Keibul Lamjao National Park

   (b) Keibul Lamjao National Park. On Loktak Lake, Manipur, this is the world’s only floating national park: phumdi (floating biomass) supports the brow-antlered sangai. That unique swamp-with-floating-vegetation is the official key.

3. C

   Keoladeo Ghana National Park

   (c) Keoladeo Ghana National Park. Bharatpur is a man-managed wetland for migratory birds, not a floating-vegetation swamp of the Loktak type. Not the key.

4. D

   Sultanpur National Park

   (d) Sultanpur National Park. A Haryana bird wetland near Gurugram, without phumdi ecology. Not the key.

Summary. Official key is (b) Keibul Lamjao National Park. It sits on Loktak Lake and is famous for floating phumdis and the sangai deer. Bhitarkanika is mangrove, Keoladeo and Sultanpur are bird wetlands without that floating-swamp character. Only Keibul Lamjao matches the stem.