Manager: One reason productivity in our office is not as high as it could be is that office workers spend too much time taking unauthorized breaks. Since the number of office workers assigned to each manager will soon be reduced, managers will be able to supervise workers more closely in the future to make sure that they are not taking unauthorized breaks. Ttherefore, productivity in our office will soon increase. Which one of the following is an assumption on which the manager's argument depends? ['Supervising employees more closely to reduce unauthorized breaks is the most efficient way of increasing overall office productivity.', 'The gain in productivity that will result from reducing unauthorized breaks will exceed any loss in productivity caused by closer supervision.', 'Giving financial incentives to workers whose divisions increase their productivity would not have any significant effect on overall office productivity.', 'The best way to improve productivity is to reduce the number of employees and give more work to employees who remain on the job.']