Conquest, war, famine, and death
It is said in the bible in the last book called Revelations
Well, it decreased the demand of Slave Labor.
Back then, the technology advancement , especially in agricultural sector, significantly increased the total production. This cause the demand of overall labor decreased. The northern US, who utilized more of this advancement more than their southern neighbor, manage to produce hundred times more output than the southern who still depended on their slave labor
The correct answer is C. Egypt I believe correct me if I am wrong!
Sunk relief is the answer