The correct answer is: c) Both a and b.
Dorbars and Rangbah Shnongs are traditional village administration bodies in the Khasi Hills, while Nokmas are traditional village administration bodies in the Garo Hills.
Dorbars are village councils that are responsible for the administration of the village. They are made up of elected representatives from each household in the village. The Rangbah Shnong is the head of the Dorbar and is responsible for presiding over meetings and making decisions on behalf of the village.
Nokmas are the traditional leaders of the Garo Hills. They are responsible for the administration of the village and for settling disputes between villagers.
Both Dorbars and Nokmas play an important role in the traditional village administration of Meghalaya. They are responsible for maintaining law and order, resolving disputes, and providing social welfare services to the villagers.