Rogers's View on Research into the Effectiveness of Person-Centered Therapy

Rogers's view on research into the effectiveness of person-centered therapy was that

A) it was important, and he was committed to carrying out research studies to prove the effectiveness of its principles.
B) it was important, but he preferred to leave the details of research methodology to others.
C) it was unimportant because the study of therapy interfered with the client therapist relationship.
D) it was unimportant because it violated important humanistic principles.