Why Do Collective (I

Why do collective (i.e., social) identities increase individuals' likelihoods of participating in a social movement, even when they can benefit from the movement without actually participating (the free rider problem) ?

A) Challenging out-group members results in positive emotions, which makes direct participation in a social movement appealing.
B) Participation in a social movement allows people to consciously choose their in-group, which gives them a sense of control over their lives.
C) People recognize that viewing themselves as activists will lead to the formation of self-enhancing relationships and self-views.
D) The formation of a collective (social) identity minimizes the distinction between individual and group interests.
E) both a and b