Which of the Following Has Not Been Shown to Be

Which of the following has not been shown to be true of children who watch aggressive television?

A) Children who watch more aggressive television at home are, on average, more aggressive than children who watch less aggressive television at home.
B) The effects of aggressive television on children are uniform.
C) Viewing aggressive TV shows has no noticeable effect on children who are not aggressive.
D) Preschool boys but not girls who watch violent made-for-children television programs display more antisocial behavior 5 years later than children who did not watch such television programs.