An overwhelming proportion of the most productive employees at SaleCo' s regional offices work not eight hours a day, five days a week, as do other SaleCo employees, but rather ten hours a day, four days a week, with Friday off. Noting this phenomenon, SaleCo' s president plans to increase overall productivity by keeping the offices closed on Fridays and having all employees work the same schedule-ten hours a day, four days a week. Which of the following, if true, provides the most reason to doubt that the president's plan, if implemented, will achieve its stated purpose? ["Typically, a SaleCo employee's least productive hours in the workplace are the early afternoon hours.", 'Those SaleCo employees who have a four-day workweek do not take any of their office work to do at home on Fridays.', 'Employees at SaleCo are compensated not on the basis of how many hours a week they work but on the basis of how productive they are during the hours they are at work.', 'Working ten hours a day has allowed the most productive employees to work two hours alone each day in their respective offices relatively undisturbed by fellow employees.']