Researchers are testing the hypothesis that high levels of carbon dioxide in the blood trigger panic attacks. Half of the participants breathe carbon dioxide-enriched air, and the other half breathe normal air, then measured panic attack symptoms. In this study is the independent variable and is the dependent variable.

The correct answer is 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.