Which two words would BEST replace "setback" and "decisively" in the selection above?

(A) obstacle; mysteriously

(B) impediment; clearly

(C) catalyst; courageously

(D) revitalization; horribly

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.