Abigail is reading about life in a particular African society. In this society, women are expected to milk the cattle twice a day and retrieve water, which they carry home on the backs of donkeys, as needed. Once every month or so, the settlement moves and each woman must move her belongings and rebuild her home. While most of the transport is done using donkeys, some older women are forced to rely on their daughters, their co-wives, and other female family members for help. Which type of economy is most likely found in the society Abigail is reading about?