When a group of children who have been watching television programs that include acts of violence is sent to play with a group of children who have been watching programs that do not include acts of violence, the children who have been watching violent programs commit a much greater number of violent acts in their play than do the children who have been watching nonviolent programs. Ttherefore, children at play can be prevented from committing violent acts by not being allowed to watch violence on television. The argument in the passage assumes which one of the following? ['Children who are treated violently will respond with violence.', 'There are no other differences between the two groups of children that might account for the difference in violent behavior.', 'Violent actions and passive observation of violent actions are not related.', 'Television has a harmful effect on society.']