Steur, Applefield, and Smith Conducted an Experiment Where Preschool Children

Steur, Applefield, and Smith conducted an experiment where preschool children were randomly assigned to two groups. One group watched cartoons containing violence, and the other group watched cartoons with the violence removed. During a free-play session, the children who watched the cartoons containing violence showed more aggression than children who watched the nonviolent cartoons. What conclusion was drawn from this study?

A) Preschool children are naturally more aggressive than older children.
B) Violent TV cartoons caused the increased aggression in the children in this investigation.
C) The cause of aggression cannot be determined since aggression is caused by so many other factors.
D) Exposure to TV violence caused the aggression in the children in this investigation.