The correct answer is Cattle. Africans didn't treat cattles as animals, rather Cattle became the pioneering form of capital in Southern Africa and introduced the idea of individual wealth. Politically, they also introduced hierarchical social systems and statecraft together with the reef mining of gold that emerged in the 12th century. Southern Africa’s inclusion in the Indian Ocean trade with the Chinese, Irano-Arabic, Hindu and Indonesian peoples created one of the greatest commercial bonds on Earth, according to historian KN Chaudhuri – a bond that influenced the formation of states in this region.