Kim's willingness to produce more T-Shirts when the price of T-Shirts is higher demonstrates: a
the law of diminishing marginal utility
b
the law of supply
c
the law of demand
d
the elasticity of demand

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.