Under the Indian Appropriations Act of 1871, the correct option is (b) Indigenous peoples were treated as individuals.
The Indian Appropriations Act of 1871 effectively ended the recognition of Indigenous tribes as sovereign nations. It prohibited the signing of new treaties with Native American tribes and shifted the focus to assimilation and individualization of Indigenous peoples. This policy aimed to break up tribal lands and allocate individual plots of land to Native Americans, with the goal of encouraging them to adopt American farming practices and customs. This act reflected a significant change in the treatment of Indigenous peoples by the US government, shifting from recognition of tribal sovereignty to an assimilationist approach that focused on treating Indigenous individuals rather than tribal entities.