Which of the Following Statements Regarding Child and Adolescent Groups

Which of the following statements regarding child and adolescent groups is NOT true?

A) Adolescent groups are more mixed or heterogeneous than children's groups.
B) Opposite-sex participation in social groups decreases in adolescence.
C) Adolescent groups are more formalized than children's groups.
D) Rules are more well-defined in adolescent groups than in children's groups.