What Is the Main Implication of the Finding Known as the Dodo

What is the main implication of the finding known as the Dodo Bird verdict?

A) It doesn't matter which psychotherapy a therapist uses because all are about equally effective.
B) A psychotherapy that can't adapt its methods to new insights will quickly become extinct.
C) Clients all have the same basic problem and eventually a single psychotherapy will evolve to address it.
D) No psychotherapy works any better than a placebo or doing nothing at all in terms of treating emotional problems.