Tribes in Saudi Arabia divide themselves into what based on family?

The correct choice is "B. Clans" because in the context of Saudi Arabian tribal society, a clan is a more specific subgroup within a tribe that often shares a common ancestor. Clans are typically comprised of multiple families that are linked through lineage and heritage. This hierarchical structure allows tribes to maintain social organization and reinforces familial ties, which are vital in the cultural fabric of Saudi Arabia. The concept of clans is central to understanding social dynamics, relationships, and allegiances within the tribal system, as they play a significant role in governance, conflict resolution, and community support.

In contrast, options like factions, groups, and families do not accurately capture the traditional and cultural significance that "clans" hold within the tribal framework of Saudi society. Factions may imply a political or ideological division, groups can be too broad and nonspecific, and while families indeed exist within clans, they do not encompass the same level of socio-organizational structure that clans provide.