Which of the following groups of states together host the largest population of the One-Horned Rhinoceros in India?

The correct answer is Assam and West Bengal . Key Points Assam serves as the primary habitat for the Greater One-Horned Rhinoceros (Rhinoceros unicornis) in India, housing approximately 2,895 individuals according to recent census data. Kaziranga National Park alone accounts for the vast majority of this population, while Pobitara Wildlife Sanctuary maintains the highest density of rhinos in the world. West Bengal is home to the second-largest population of one-horned rhinoceroses in the country. The population is concentrated within the Jaldapara National Park and Gorumara National Park , which provide the essential alluvial grasslands required for their survival. The combination of these two states encompasses the core Terai-Duar savanna and grasslands ecosystem, which is the natural biographical zone for this mega-herbivore in the Brahmaputra and Ganges river basins. Additional Information Greater One-Horned Rhinoceros : Conservation Status : It is listed as Vulnerable on the IUCN Red List and protected under Schedule I of the Wildlife Protection Act, 1972 . Physical Characteristics : It is identified by a single black horn and a grey-brown hide with skin folds that give it an armor-plated appearance. Indian Rhino Vision 2020 (IRV2020) : An ambitious program launched in 2005 to attain a population of 3,000 rhinos spread over seven protected areas in Assam . Regional Context of Other Options : Gujarat and Rajasthan : These states are primarily known for Asiatic Lions (Gir) and Great Indian Bustards ; their arid climates are unsuitable for rhinos. Kerala and Tamil Nadu : These regions in the Western Ghats host large populations of Asian Elephants and Bengal Tigers but lack the specific grassland habitats required by rhinos. Bihar and Jharkhand : While Bihar contains a small population in Valmiki National Park , it does not compare to the significant numbers found in the Assam-Bengal belt.