Which of the Following Best Describes Trade Along Africa's East

Which of the following best describes trade along Africa's east coast during the thirteenth and fourteenth centuries?

A) East African seaports were small and lay at the fringes of Afroeurasia's trade routes.
B) Only Muslims were permitted to trade along the East African coast.
C) Unusual for its time, East African merchants refused to participate in the slave trade.
D) East African ports were an important part of the trans-hemispheric trade routes and brought parts of inland Africa into the larger commercial networks of the day.