Which of These Is NOT Identified in the Text as a Difficulty

Which of these is NOT identified in the text as a difficulty in assessing the effectiveness of therapies?

A) A client may function satisfactorily in society but still perceive themselves to have impaired psychological well-being
B) Clients treated by different forms of therapy may vary in the severity of their symptoms
C) Some clients have better support structures outside of therapy than others
D) Therapy that appears effective initially may not be effective in preventing relapse (return of symptoms)
E) Fourth, most waiting-list clients active seek ways of coping with their lives while awaiting therapy