The correct answer is the Sarus Crane.
The Sarus Crane is a large, long-legged bird with a long neck and a red crown. It is the tallest flying bird in the world, with a height of up to 1.8 meters. The Sarus Crane is found in open grasslands, wetlands, and agricultural areas in India, Pakistan, Nepal, and Bangladesh. It is a social bird that lives in flocks of up to 100 birds. The Sarus Crane is an important part of the Indian culture and is considered to be a sacred bird. It is also the state bird of Bihar.
The Indian House Sparrow is a small, brown bird with a short tail and a long, pointed bill. It is found in urban and rural areas throughout India. The Indian House Sparrow is a social bird that lives in colonies of up to 100 birds. It is an important part of the Indian ecosystem, as it helps to control pests and pollinate plants.
The Indian Peafowl is a large, colorful bird with a long tail. It is found in forests and grasslands throughout India. The Indian Peafowl is a social bird that lives in groups of up to 10 birds. It is an important part of the Indian culture and is considered to be a royal bird.
The Asian Koel is a medium-sized, black bird with a white belly. It is found in forests and woodlands throughout India. The Asian Koel is a brood parasite, which means that it lays its eggs in the nests of other birds. The host birds then raise the Koel chicks as their own.
The Sarus Crane is the state bird of Bihar because it is a native bird of the state and is an important part of the Indian culture. The Indian House Sparrow, Indian Peafowl, and Asian Koel are not native to Bihar and are not as important to the Indian culture as the Sarus Crane.