The statement that best describes a form of slavery not traditionally practiced in Africa is "a system in which people are enslaved permanently on account of their race."
While various forms of servitude and slavery existed in Africa, they did not typically adhere to the racially based, permanent chattel slavery seen in the Americas and other regions. Rather, many systems of servitude in Africa were often based on factors such as debt, warfare, and social status, and could sometimes allow for the possibility of integration into the society or eventual freedom.