For a large part of the 20th century, only a small part of the population in south africa had a say in the government. certain racial groups, including blacksnot allowed to vote. the ruling class was made up mostly of white citizens. this system lasted until the 1990s. based on this information, what type of government did south africa most likely have? the answer is oligarchy

Yes, oligarchy fits as a description of South African government under the system of apartheid.  In the political philosophy of Aristotle, "aristocracy" is "rule by the excellent ones," and in certain eras of history or in some societies, one group or another has been portrayed as more "excellent" and thus more favorable for serving as governors.  In Aristotle's political thought, an "oligarchy" or "rule by a few" is a corruption of the idea of aristocracy.  But Aristotle was biased, believing that by nature some persons are more excellent than others, that some are more suited by nature to be followers, not leaders. (Aristotle used such logic in defending the institution of slavery, for instance.)   Today, we might argue that any sort of "aristocracy" or elitism is always an oligarchy, an arbitrary system in which a few dominate over the many because of factors that can't rationally be defended.

For another answer on a similar question, read more on -