In the context of family systems theory, identify a true statement about the belief of family therapists.
1) They believe that a problem child would make steady improvements in his or her functioning.
2) They believe that the family system has a weak impact on a child's behavior.
3) They believe that working with an individual alone produces long-term change in a child's behavior.
4) They believe that a problem child often reverts back to problem behaviors unless the family changes.