Explanation

– Pair 1 is correctly matched: The Blue-finned Mahseer (*Tor khudree*) is an iconic freshwater game fish native to the peninsular rivers of India, thriving naturally in the Cauvery River basin.
– Pair 2 is incorrectly matched: The Irrawaddy Dolphin (*Orcaella brevirostris*) is a coastal and estuarine euryhaline dolphin inhabiting river mouths, estuaries, and lagoons (notably the Chilika Lake in Odisha and Sundarbans). In the Chambal River, the resident freshwater cetacean is the Ganges River Dolphin (*Platanista gangetica*), not the Irrawaddy dolphin.
– Pair 3 is correctly matched: The Rusty-spotted Cat (*Prionailurus rubiginosus*), the world’s smallest wild cat, is endemic to India and Sri Lanka and is naturally found across dry deciduous forests and scrublands of the Eastern Ghats and central Indian woodlands.

Hence, pairs 1 and 3 are correctly matched — Option C.