Which of the Following Statements Concerning Slavery on the Continent

Which of the following statements concerning slavery on the continent of Africa before the arrival of the Europeans is most accurate?

A) Most African societies were egalitarian, that is, most people enjoyed the same social status, and slavery was unknown.
B) Slavery in Africa was restricted to those areas where Islamic influence had introduced the concept in the period after the 7th century.
C) While common elsewhere in Africa, slavery was not common in the forest states of west Africa prior to the coming of the Europeans.
D) Since in many African societies all land was owned by the state of the ?ruler,? the control of slaves was one of the few ways in which individuals or lineages could increase their wealth and status.