In dr. strayer's longitudinal research on factors that correlate with getting older, she is likely to find that:

The answer is most people maintain their intellectual abilities as they age
Even though as people got older our cognitive capability tend to decrease, we will definitely collected far more experience than we're young.
This make us able to analyze a problem with more efficient point of view, which contribute to our overall intelligence.

The answer should be a.

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.