How did africas geographic features influence migration, cultural development, and trade

The African geography had influenced the continent on all levels to diversify into two separate large areas. The two areas are North Africa, or Saharan Africa, and sub-Saharan Africa, the part south of the Sahara Desert.

The Sahara Desert is a big, hostile, harsh natural border between the northern part of the continent and the central and southern part of it. Because of it, people in the northern part developed unique cultural traits, and the people from the sub-Saharan part developed unique cultural traits, and they did not influenced each other because of the isolation and little to no contact between them.

The migration through the Sahara was pretty much a suicide, so rarely who dared to try and migrate through it, yet alone carry trading goods and try to cross it and trade with the people further north.

the answer is option a.

less available tax revenue

this basically means that when they get money from taxes wirth having a lower gdp they get less then what others have with a higher gdp