Correct Option
Critical Tiger Habitat (CTH) refers to the core areas of tiger reserves notified under the Wildlife Protection Act, 1972 (amended in 2006), which are to be kept inviolate for the purpose of tiger conservation. Nagarjunsagar-Srisailam Tiger Reserve, spanning parts of Andhra Pradesh and Telangana, possesses the largest notified CTH among the given options and in India, with an approximate area of 3720 km².
Incorrect Options
Corbett Tiger Reserve has a CTH of approximately 1290 km², which is considerably smaller than that of Nagarjunsagar-Srisailam.
Ranthambore Tiger Reserve's CTH is approximately 1110 km², significantly less than Nagarjunsagar-Srisailam.
Sunderbans Tiger Reserve has an approximate CTH of 1700 km², also smaller than Nagarjunsagar-Srisailam.