What term describes the brotherhoods into which the people of Athens were divided?

The term that describes the brotherhoods into which the people of Athens were divided is "phratries." In ancient Athens, phratries served as social units that organized citizenry into smaller groups, fostering kinship and community among members. They were significant in the context of Athenian society, as each phratry would often share ancestral ties and participate in religious and civic functions. This organization helped to manage social relationships and facilitated participation in the political sphere.

The other terms do not accurately represent the specific structure of Athenian society. Tribes refer to larger divisions within Athenian society, each comprised of several phratries, while sects usually denote religious groups or denominations, which is not applicable in this civic context. Factions indicate groups formed around political alliances or rivalries, which, although relevant to Athenian politics, are not the same as the brotherhoods described by phratries. Thus, phratries specifically align with the idea of brotherhoods in Athenian society.