Q21:

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?

A    Typically, a SaleCo employee’s least productive hours in the workplace are the early afternoon hours.

B    None of the employees who work four days a week had volunteered to work that schedule, but all were assigned to it by their supervisors.

C       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.

D     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.

Answer: C

根据我的理解，削弱的时候应该是说这个方法不能提高productivity~~c选项的话，有两小时undisturbed by fellow employees怎么会是削弱呢？