What effects did trade have on the kingdoms of west africa?

When kingdoms of West Africa did trading, they got stuff back and it influenced their cultures heavily from what they received in return.

The answer should be b

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.