Disease and violence from other groups
C because dominating 80% of global supply for the materials that are essential to much of today's high-end tech.
According to the graph, we can say that <span>
Nigeria was generating greater revenue from oil in 1990 compared to previous years. </span><span>If we look on the table, we can see how the oil industry has covered more of the economy, so if it went down, Nigeria would get in serious economical problems.</span>
Byzantium/Constantinople was conquered in 1451, but the empire continued to decline starting around the 18th or 19th centuries. It officially died in WWI. As for how long it was a major threat to Europe, the empire's prime was the 16th century, under Suleiman the Magnificent.