Answer;
The natural advantage the kingdoms of West Africa had was an abundance of natural resources including salt and gold.
Explanation;
The major advantage of the West Africa kingdom was abundance of resources such as gold and salt, in addition the trans-Saharan trade played a great role.
These kingdoms acquired wealth through control of the gold trade in the region. Salt was valuable to western Africans for replenishing the body, preserving food, and its good taste.