https://socratic.org/questions/how-were-the-west-african-kingdoms-involved-in-the-slave-trade
With the development of the trans-Saharan slave trade and the economies of gold in the western Sahel, a number of the major states became organized around the slave trade, including the Ghana Empire, the Mali Empire, and Songhai Empire. However, other communities in West Africa largely resisted the slave trade.
The transatlantic slave trade began during the 15th century when Portugal, and subsequently other European kingdoms, were finally able to expand overseas and reach Africa. The Portuguese first began to kidnap people from the west coast of Africa and to take those they enslaved back to Europe
An oligarchy- by definition- means, “A small group of people having control of a country, group, or organization.” (Source for definition: “Google”)
The answers not supported by this definition are: B, C, and D, as B and C are citizen-contributed systems, and D is a monarchy/dictatorship.
This leaves us with answer “A” being the only plausible answer to fit our description.
I hope this helps!
The primary way in which the government encouraged settlement in the west was through the Homestead Act, which gave people free land--while the railroads allowed them to travel there safely.
His speech, was about putting people back to work. Due to lack of employment cause that era was in the Great Depression.