Which of the Following Criticisms of Masters and Johnson's Work

Which of the following criticisms of Masters and Johnson's work was advanced by Zilbergeld and Evans (1980) ?

A) They reported a non-failure rate which may have included both successes and failures.
B) Masters and Johnson never adequately defined what they meant by "success" in therapy.
C) Masters and Johnson never provided a clear definition of what they considered a "failure" in therapy.
D) All of the answers are correct.