The two popular assemblies which seem to have formed an essential feature of the government during the Age of Rig Veda are:

Answer: Option B

Sabha:
Sabha was the assembly in early Rig-Vedic and the assembly hall in later Rig-Vedic period. Women who attended this assembly were known as Sabhavati. It was a kin based assembly.

Samiti:
Samiti was a folk assembly in which people of the tribe gathered for transacting tribal business. It discussed philosophical issues and was concerned with religious ceremonies and prayers.