Recall that researchers (Pennebaker & Sanders, 1976) placed one of two signs in the bathrooms on a college campus. One was a strong warning ("Do not write on these walls under any circumstances") and the other was a milder admonition ("Please don't write on these walls"). Two weeks later, what were they likely to find in the bathrooms containing the strong warnings?
a. scrawls that read "Says Who?" and "What Are You Going to Do About This?"b. graffiti in the stalls, but not on the walls where the sign was postedc. walls that were relatively cleand. less graffiti, but signs posted everywhere

The answer is letter A: In the bathrooms containing the strong warnings they likely to find scrawls that read "Says Who?" and "What Are You Going to Do About This?".

Explanation:

The reason people are likely to react that way is explained by the Reactance Theory (when persuasion attempts boomerang); because when people feel like their freedom of doing the graffiti, for example, is threatened so they react with an unpleasant state of defiance and by that they feel like their sense of personal choice is restored.