The correct answer is C) Slavery already existed in Africa before the arrival of Europeans.
The statement that is true about slavery is " Slavery already existed in Africa before the arrival of Europeans."
Indeed there are many examples in the history of ancient Egypt where people were slaves serving the Pharaoh. When the Egyptian troops defeated another army, the Egyptians took prisoners to work as slaves in the Egyptian kingdom. Let's remember the ages of one the Old Testament books called the "Exodus," in which Moses liberated the tribe of Israel from Egyptian slavery and took them to the promised land.
