Research Comparing Therapists with Varying Types and Amounts of Training

Research comparing therapists with varying types and amounts of training has found that

A) the effectiveness of a therapist is directly proportional to his or her years of experience.
B) for patients with mild disorders, a therapist trained in psychiatry is more effective than one trained in psychology.
C) therapists who received their doctorate degree after 1986 are generally more effective than those who received their education earlier.
D) therapists with different types of training are about equally effective, on average.