求助几道GWD的逻辑

amy虫子

GWD6-Q20:
Five years ago, as part of a plan to encourage citizens of Levaska to increase the amount of money they put into savings, Levaska’s government introduced special savings accounts in which up to $3,000 a year can be saved with no tax due on the interest unless money is withdrawn before the account holder reaches the age of sixty-five.  Millions of dollars have accumulated in the special accounts, so the government’s plan is obviously working.
Which of the following, if true, most seriously weakens the argument?
plan 的目的是增加储蓄
D.    Many Levaskans who already had long-term savings have steadily been transferring those savings into the special accounts. 许多人将已有的长期储蓄里的存款赚到了special account,所以总的储蓄没有增加

GWD6-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?
文章说，最有效率的员工一个星期是工作四天，每天工作10小时，其他员工一天工作8小时
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. 那些工作10小时的有效率的员工有两个小时是不受其他人干扰的， 那如果大家都工作10小时，那就有干扰了，效率就差了