The correct answer is: a) Great Indian Hornbill.
The Great Indian Hornbill is a large hornbill found in the forests of India, Nepal, Bhutan, Bangladesh, Myanmar, and China. It is the state animal of Nagaland. The Great Indian Hornbill is a large, black bird with a white neck and chest. It has a long, curved beak and a large casque on its head. The Great Indian Hornbill is a social bird that lives in groups of up to 12 birds. It is a frugivore and feeds on fruits, berries, and insects. The Great Indian Hornbill is a monogamous bird and pairs for life. The female lays 2-3 eggs in a nest that is built in a tree. The eggs hatch after about 30 days and the chicks are cared for by both parents. The Great Indian Hornbill is a vulnerable species and is threatened by habitat loss and hunting.
The other options are incorrect for the following reasons:
- Option b, Clouded Leopard, is a large cat found in the forests of Southeast Asia. It is not found in Nagaland.
- Option c, Mithun, is a wild cattle found in the forests of India and Nepal. It is not a bird.
- Option d, Hoolock Gibbon, is a small ape found in the forests of Southeast Asia. It is not found in Nagaland.