Which of the Following Statements Is True Regarding Group Norms

Which of the following statements is true regarding group norms?

A) norms are explicit rules about the acceptable behaviours and attitudes in a group
B) norms are beliefs that are shared by the members regarding acceptable behaviours in the group
C) violation of group norms leads to immediate ostracism
D) norms are rigid rules that tell group members how to behave in many social situations
E) none of the above