A Clinical Researcher Is Particularly Interested in Learning Whether Systematic

A clinical researcher is particularly interested in learning whether systematic desensitization is more or less effective with particular people suffering from anxiety. To do this, he collects personality measures from people receiving this treatment and looks to see whether certain personality traits are associated with the effectiveness of the outcome. With regard to the "specificity question," this study is most concerned with studying the importance of:

A) different types of client variables.
B) different types of therapies.
C) different types of eclecticism.
D) different types of therapist variables.