The sentence that best explains why Angola and Cuba experienced different economic conditions than Algeria and Belize in the late 20th century is Algeria and Belize were largely self-sufficient and avoided the worst effects of the global financial meltdown.
What can be deduced from the graph?
The fact that Algeria and Belize were mostly self-sufficient and spared from the worst consequences of the global financial crisis is the greatest explanation for why Angola and Cuba saw different economic circumstances in the late 20th century than did Algeria and Belize.
The state still controls the majority of Algeria's economy, a holdover from the socialist era. The tourism, retail sales, and finance sectors account for almost 75% of the GDP. Angola lost all of its correspondent links with foreign countries in late 2016, both in developed nations and in areas with favorable weather.