How is a family group or clan making the decision that the settlement will grow barely and other grains and example of the advancement of the civilization? a: it shows that a central group is organize and making decisions as a government which is a sign of civilization b: it shows that the civilization has capable leader who know that barley and other grains will grow well in the region. c: it shows that no one else is experienced enough in agriculture to make decisions that will affect the strength of the civilization economy. d: it shows that a central groups is hopeful that other nearby civilization will want to buy barely and other grains in exchange for other crops?