What is the basic premise of family therapy? Family members should be convinced by a…

What is the basic premise of family therapy?
Family members should be convinced by a therapist to urge a member with psychological problems into treatment.
The purpose of therapy is to identify which family member has the greatest need for psychological treatment.
Psychological issues affecting even one family member can affect the entire family unit.
Humanity is one big family; what affects a single individual affects us all.