Mary spends a lot of time with her crowd, or peer group. she uses their language and adopts the preferred clothing styles for girls in her group. for mary, her peer group is a/an a. primary group. b. secondary. c. ethnic group. d. dyad.

The correct answer is A. a primary group.
Primary group refers to individuals following other people's example when doing something. Here, Mary started using the language of that particular group and dressing like them. Thus, they represent her primary group in her life.