In 1987, the united nations general assembly passed a resolution that prohibited countries from buying oil from south africa in an effort to persuade the nation to end the racist policies of apartheid. this is an example of a(n)

economic sanction

Explanation:

In 1987, the international community decided to impose strict economic sanctions on the Republic of South Africa in order to force it to end the apartheid. The sanction was directly imposed on the oil, which was a big blow for the economy of the country as it provided large portion of the income. This economic sanction resulted in stopping of the apartheid, thus it had its purpose accomplished, leading to a much more equal society, opportunities for everyone, education for everyone, and ending the segregation in this nation.

answer; conditional stimulus will trigger a conditioned response;