In the Trans-African slave trade, other things were traded besides human cargo. The Arab nations along the Mediterranean Sea and the tribal nations of Sub-Saharan Africa were dependent on each other for the commodities of gold and salt Which BEST describes why these two regions were dependent on each other?

A)They both disliked the Europeans, and because of that only traded with
each other

B) They shared a common religion and that made each region highly
dependent on the other

C) They each had one of the commodities but not the other, so they needed
their trading partner to provide it

D) They each had a surplus of those commodities, so the easiest thing to do
was to give that surplus to the other one.

Thank you for your help! Much appreciated-
No links please thx

Given that the Arab nations along the Mediterranean Sea possess the capacity to mine salt, but not gold, while they value gold as a means of wealth and riches, the sub-Saharan African region, in contrast, can mine gold but not salt, while they value salt in making preservations and food cooking. Thereby there is a need for the two regions to be trading partners to provide their needs.