Which of the following is not an example of a nonexperimental or quasi-experimental study? a. a study comparing self-esteem scores for children with a learning disability versus scores for children...

Which of the following is not an example of a nonexperimental or quasi-experimental study?

a. a study comparing self-esteem scores for children with a learning disability versus scores for children without a learning disability

b. a study comparing depression scores before therapy versus scores after therapy

c. a study comparing performance in a room where the walls have been painted yellow versus performance in a room painted blue

d. a study comparing attitude scores for men versus scores for women