The growth of major sub-saharan african kingdoms and empires was by
a. agriculture and trade
b. language and religion
c. religion and agriculture
d. language and agriculture

The growth of Sub-Saharan African Kingdoms was assisted by Agriculture and Trade.  Increase in trade routes led to increase in transportation that played a major in increasing the trade activities that led to flourishing of these kingdoms, the major exports included slaves, gold, copper and animal products such as ivory, pelts, feathers and tortoise shells. 

Is there a passage that comes with this question or should i know this right off the bat, because if it is, i probably have short term memory loss or college is too stressful