I think it will be D if I remember that right
In the ancient world, slavery developed for a number of reasons including economic necessity especially in civilizations and agricultural economies where larger workforces were needed. Domination was another factor.
The cities were flooded by new arrivals from European countries and African Americans.
<u>Explanation:</u>
The whites were seeking opportunities to work in the industries with the coming up of urbanisation and industrialisation new opportunities were arising.
On the other hand the African Americans freed themselves from the farms and owners who didn't provide them with facilities. They came in search of some benefits and jobs just like other immigrants.
Though they were very easily targeted with the racial discrimination haltered. But they came in hopes to find better living conditions.
"The fifteenth amendment of United States Constitution prohibits the federal and state governments from denying a citizen the right to vote based on that citizen's "race, color, or previous condition of servitude "