As Compared to Aggregations of Nursery Schoolers, the Group Activities

As compared to aggregations of nursery schoolers, the group activities of grade-school children are characterized by

A) shared norms created by the group
B) assumptions of relatively stable roles and statuses by group members
C) rapidly fluctuating membership
D) shared norms created by the group and assumptions of relatively stable roles and statuses by group members
E) all of these