B- Popular opinion turned against South African apartheid.
Explanation:
American public opinion and Congress started to feel increasingly angry about the apartheid regime. In the early 1980s, there were more and more calls for sanctions against Pretoria. This forced the US Ronald Reagan administration to make a policy shift. Pressure was added after Nobel Peace Prize winner, South African archbishop Desmond Tutu went to the United States and publicly called US policy "immoral."
