Which of the Following Is an Example of a Situation

Which of the following is an example of a situation in which economic sanctions accomplished the intended goal?

A) sanctions levied against South Africa in the mid-1980s to protest apartheid
B) the grain embargo on the Soviet Union in 1980 in retaliation for the Soviet invasion of Afghanistan
C) the sanctions against Cuba to oust the Marxist dictator -Consider This: The Marxist regime was still in power 50 years after sanctions were first imposed.
D) sanctions imposed on Russia to keep it out of Crimea