Which of the Following Statements Is True

Which of the following statements is true?

A) Ibn Battuta was given a young female slave when he visited the court.
B) The people of Mali did not enslave their own countrymen, they captured slaves from the forest belt to the south.
C) About five hundred slaves were sold north of the Sahara each year.
D) Slaves in Mali were only males.
E) Slaves were only captured in war.