Which of the Following Studies Is Based in Cognitive Dissonance

Which of the following studies is based in cognitive dissonance theory?

A) Children who brushed their teeth every day for a week received a new toy.
B) Women received a brochure describing the costs of not engaging in regular breast self-exams.
C) Adult smokers were told that they were in the top 20% in their ability to successfully give up cigarettes.
D) Adolescent girls were asked to discuss how to help others avoid body image problems, write an essay about the costs of pursuing the thin ideal, and role-play convincing someone not to adopt the thin ideal.