Answer : 2. "Arunachal Pradesh"
Explanation :

After an absence of 42 years, the Namdapha flying squirrel (Biswamyopterus biswasi) has been rediscovered in Arunachal Pradesh. It is endemic to Arunachal Pradesh. Last described in 1981, this species was thought to be extinct or confused with a similar species. It is classified as Critically Endangered (CR) by the IUCN and listed under Schedule II of the Wildlife Protection Act. It was one of the 25 “Most Wanted Endangered” species targeted by Global Wildlife Conservation's “Search for Lost Species” initiative.