Reuben's boss recently took him off probation because Reuben had met performance standards that he and his boss had agreed upon. This is an example of a reinforcement

The correct answer is negative

Reinforcement must maintain a certain behavior and that its tendency is to increase the emission of responses. With Negative Reinforcement, even with the connotation of negation in its complementary name, exactly the same thing occurs.

Negative Reinforcement, mean that something has been removed from the organism's environment, causing the behavior to be maintained.

the above statement/question is (true);

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.