Correct Option
All three species listed, Gharial, Leatherback turtle, and Swamp deer, are classified under threatened categories by the International Union for Conservation of Nature (IUCN).
- Gharial (Gavialis gangeticus): This species is classified as Critically Endangered. It is primarily found in the freshwater river systems of the Indian subcontinent, particularly the Ganga and its tributaries. Major threats include habitat loss, sand mining, pollution, and entanglement in fishing nets.
- Leatherback Turtle (Dermochelys coriacea): This species is classified as Endangered. Its threats include bycatch in fishing gear, plastic pollution, coastal development, and illegal poaching of eggs and adults.
- Swamp Deer (Rucervus duvaucelii), also known as Barasingha: This species is classified as Endangered. It is endemic to the Indian subcontinent and typically found in specific wetland and grassland habitats. Key threats include habitat degradation, wetland drainage for agriculture, and poaching.
Incorrect Options
Options 1, 2, and 4 are incorrect because they exclude one or more species from the list that are indeed classified as endangered or critically endangered by the IUCN. Since all three species (Gharial, Leatherback turtle, and Swamp deer) are under threatened categories, the option including all three is the correct one.