The correct answer is D. Nyaya Panchayat.
A Gram Sabha is a general body of all the adult members of a village. It is the basic unit of Panchayati Raj. The Gram Sabha is responsible for discussing and deciding on all matters of local importance.
A Gram Panchayat is a local self-government body at the village level. It is constituted by elected representatives from the village. The Gram Panchayat is responsible for the development and management of the village.
A Gram Cooperative society is a cooperative society formed by the villagers for their common benefit. The Gram Cooperative society can be formed for any purpose, such as agriculture, marketing, or credit.
A Nyaya Panchayat is a village court that settles disputes between villagers. The Nyaya Panchayat is composed of elected representatives from the village. The Nyaya Panchayat is not a Panchayati Raj Institution because it is not a local self-government body.