Despite the Best Treatment Some Patients Show a Lack of Significant

Despite the best treatment some patients show a lack of significant improvement because

A) most of the time clinicians fail to make a proper primary diagnosis.
B) they may lack the willingness to break old patterns of behavior.
C) recent data reveals that short-term goals are more successfully achieved than long-term goals of treatment.
D) modern medical science is not equipped to deal with major mental disorders.