The correct answer is: B. Sabha and Samiti.
The Sabha and Samiti were two popular assemblies which seem to have formed an essential feature of the government during the Age of Rig Veda. The Sabha was a council of elders, while the Samiti was a larger assembly of all free men. Both assemblies had the power to make laws and decisions, and they played an important role in the government of the Vedic period.
The Sabha was a council of elders, and it was the most important of the two assemblies. The Sabha was composed of the heads of families, and it was responsible for making laws and decisions. The Sabha also had the power to elect the king, and it could depose him if he was not a good ruler.
The Samiti was a larger assembly of all free men. The Samiti was not as powerful as the Sabha, but it could still make laws and decisions. The Samiti also had the power to declare war and peace.
The Sabha and Samiti were both important parts of the government of the Vedic period. They played a role in making laws, decisions, and electing the king. The Sabha was the more powerful of the two assemblies, but the Samiti also had an important role to play.
The other options are incorrect because they are not the names of the two popular assemblies which seem to have formed an essential feature of the government during the Age of Rig Veda.