Reference groups provide us with: the ability to be concerned with accomplishing a task strict conformity to rigid organizational structures the impersonal anonymity of modern life a standard for judging one's attitudes and behaviors an organizational system by which to judge the behaviors of others

Last option is the correct answer.

Explanation:

A reference group could be defined as one that sets or establishes the standard to compare individuals or other groups - behavior and attitudes are important, but not the only things: incomes, expenses, among others could be required as part of the reference group, in example. This way, it is possible to judge others' behavior.