Editorial: The structure of the present school calendar was established to satisfy the requirements of early-twentieth-century agricultural life. In those days, farmers needed their children to have long breaks during which they could remain at home and help with the harvest. The contemporary school year is thus made up of periods of study interspersed with long breaks. But agricultural life no longer occupies most of our citizens, so we can now make changes that serve the interests of children. Ttherefore, long breaks should be removed from the school calendar. Which one of the following is an assumption on which the editorial's argument depends? ['During long breaks children have a tendency to forget what they have learned.', 'A change in the present school calendar that shortened breaks would serve the interests of agricultural life.', 'A school calendar made up of periods of study without long breaks would serve the interests of children more than a school calendar with long breaks.', "Long breaks in the school calendar should be replaced with breaks that are no longer than workers' average vacations."]