Thomas is a heavy smoker. Although no signs prohibiting smoking are visible in his college classroom, he chooses not to smoke and instead chews gum until the class is over. Thomas is abiding by the social , or rules, of the classroom.

norms

Explanation:

Social norms, or customs, are unwritten behavioral guidelines that are deemed acceptable in a community or culture. These social norms are vital for the stability and predictability of a society. People who follow these norms are well adjusted in group and those who don't follow the norms will be disapproved or even excluded from the group. As per the question, Thomas's decision to choose not to smoke in the class reveals his zeal to be accepted in class.