Buxa Tiger Reserve is a tiger reserve and national park in northern West Bengal, India, covering an area of 760 km2 (290 sq mi). In altitude, it ranges from 60 m (200 ft) in the Gangetic Plains to 1,750 m (5,740 ft) bordering the Himalayas in the north. 

Buxa Tiger Reserve forest has rich variety of  Flora and Fauna:

• Due to heavy rainfall tropical rainforests and Savannah forests are abundant. Buxa Tiger Reserve is also home for variety of unique plants. Main species of Flora in Buxa Tiger Reserve are Sal, champ, Gamar, Simul & Chikrasi. Apart from the above around more than 300 species of trees, 250 species of shrubs, 400 species of herbs, 9 species of cane, 10 species of bamboo, 150 species of orchids, 100 species of grass and 130 species of aquatic flora including more than 70 sedges (Cyperaceae) have been identified so far. There are more than 160 species of other monocotyledons and ferns.
• Around 284 species of birds and numerous butterflies add colour to Buxa Tiger Reserve forest. Buxa Tiger Reserve has the highest number of fish species in North Bengal. Narathali Lake is home to migratory birds as well as endemic ones. Apart from the above 76species of Mammals, 90 species of Snakes, 8 species of Amphibians have been identified. Apart from Tigers animals like Elephants, Leopard, Himalyan black Bears, Civets, Giant squirrel, Gaur, Wild dog, there are 04 spices of deer like -Chital, Sambar, Spoted , Barking and Hok deer. Another there Royal Bengal Tiger , Clouded leopard, Leopard , Wild Buffaloes, and Snakes including the Regal Python are found here. One of the rarest birds in India the Black – Necked Crane has been sighted in Buxa Tiger Reserve during winter.
• Indian Tiger, Leopard Cat, Bengal Florican, Regal Python, Chinese Pangolin, Hispid Hare, Hog Deer are some endangered species in Buxa Tiger Reserve.

Hence, Option B is Correct.

Jaldapara National Park is a national park situated at the foothills of the Eastern Himalayas in Alipurduar District of northern West Bengal, India, and on the banks of the Torsa River. Jaldapara is situated at an altitude of 61 m and is spread across 216.51 km2 (83.59 sq mi) of vast grassland with patches of riverine forests.

Flora and Fauna:

• The forest is mainly savannah covered with tall elephant grasses. The main attraction of the sanctuary is Asiatic one-horned rhinoceros. The sanctuary holds the maximum number of rhinos population in India after Kaziranga National Park in Assam. The other animals consists of Royal Bengal Tigers, elephants, deers, sambhar, barking deer, spotted deer and hog deer, wild pig, bisons. The wild life, in addition to the famous Great Indian One Horned rhinos, consists of Royal Bengal Tigers, wild elephants, deers, swamp deers, hog deers, wild pigs, bisons. Some rare species like the hispid hare and the hog-badger are also found here. Besides wildlife viewing, there is scope for unusual holiday activities like elephant riding and leisurely strolls through the towering grass.
• Jaldapara is a paradise for bird watchers. It is one of the very few places in India, where the Bengal Florican is sighted. The other birds to be found here are the Crested Eagle, Pallas’s Fishing Eagle and shikra, besides Jungle fowl, peafowl, patridges, Bengal Florican and lesser Pied Hornbill. Python, monitor lizards, kraits, cobras, geckos and about 8 species of fresh water turtles have also found sanctuary here. Many of the animals are endangered like – the Asiatic one-horned rhino and elephants in Jaldapara sanctuary.
• Jaldapara is also home to almost 240 species of birds, 20 species of mammals and various species of reptiles and fishes

Hence, option D is correct.

The Sundarbans National Park is a national park, tiger reserve and biosphere reserve in West Bengal, India.

Fauna in Sunderbans National Park

• The Sunderbans offer a unique ecosystem and a rich wildlife habitat. As per the 2011 tiger census, the Sunderbans had around 270 tigers. Frequent tiger attacks take place in the Sunderbans. Other than the star highlight of the Sunderbans, the endangered Royal Bengal Tiger, there is more wildlife found. Surrounded by mangroves, the Sunderbans offer habitat to a variety of species like crabs, small fishes, crabs, shrimps and more. Other than these, one can spot fauna like wild boars, fishing cats, macaques, common grey mongooses, foxes, jungle cats, flying foxes, pangolins, and spotted deer at the Sunderbans.

Flora

• Mangrove ecosystem is a very specialised environment occurring in between the terrestrial habitat and the sea in the tropical and sub-tropical regions. Sundarban is the largest delta formed by the confluence of the Ganges, Brahmaputra and Meghna rivers in the Bay of Bengal. Tide- dominated funnel-shaped estuary is intersected by mesh-like network of rivers, channels and creeks. The transitional habitat supports a unique variety of plant community, known as ‘mangrove’. The term ‘mangrove’ is derived from a Portuguese word ‘mangue’, which means salt tolerant plants. The Sundarban is one of the prominent examples of mangrove in the world.

Hence, Option A is Correct.