I think that it’s b because it’s kinda like what goes along with the question and what makes sense the most!!!!!
Pastoralism persisted in areas that could not sustain long-term agricultural pursuits, such as areas with unfavorable climates and unreliable sources of pastures, food sources, and water
Pastoralists we're vital in the spread of technological innovation between different agricultural communities as they moved between settled populations.
Li Yuan who became emperor Gaozu <span />
Is solidified constitutionial reforms by creating the national assembly