Final answer:
Trading centers promoted regional development in West African kingdoms.
Step-by-step explanation:
The conclusion supported by the information and knowledge of West Africa is that trading centers promoted regional development.
The emergence of cities in West African kingdoms, such as Koumbi Saleh, Djenne, Timbuktu, and Gao, were major sites of trading activity. These cities were centers of trade where goods like gold, salt, and other commodities were exchanged. The trading networks and economic activities in these cities played a significant role in the development and prosperity of the West African kingdoms.
For example, the Mali Empire, which grew from the city of Gao, became wealthy and powerful due to its control over the trans-Saharan trade routes. The wealth generated from trade allowed the empire to build major cities with elaborate mosques and libraries. Similarly, the Songhai Empire, which broke away from Mali, also relied on trading centers like Timbuktu for its economic and cultural advancement.