Final answer:
Wealth for those who started mining businesses in South Africa came primarily from the discovery and control of valuable mineral resources, notably gold, under a system that was heavily influenced by racial segregation and colonial policies.
Step-by-step explanation:
Those in South Africa who started mining businesses primarily became wealthy through A) Discovering new and valuable mineral resources. The gold rush in 1886 led to a massive increase in wealth for those controlling the mines, as South Africa produced over 25 percent of the world's gold. This period also saw strict governance and segregation within mining culture, with living conditions and wealth distribution heavily influenced by racial and ethnic divisions. Extractive industries like mining had always been central to the colonial imperialistic endeavors, with European colonizers and their descendants exploiting the continent's rich mineral resources, denying local Africans the profit from their natural wealth and forcing them into labor. Mining not only contributed to national wealth but also created opportunities for those who controlled the mines to amass personal fortunes.