Which Statement Is the Most Accurate About Research on the Efficacy

Which statement is the most accurate about research on the efficacy of paradoxical intention?

A) Paradoxical intention is rarely effective.
B) Paradoxical intention is primarily associated with negative outcomes.
C) Meta-analyses of paradoxical intention research have shown a large and significant effect size, but it's still considered a somewhat risky approach.
D) There hasn't been any research conducted on paradoxical intention.
E) Paradoxical intention is always unethical.