问一道prep08逻辑题~谢谢各位大牛！

wsw731

Two computercompanies, Garnet and Renco, each pay Salcor to provide health insurance fortheir employees.  Because early treatmentof high cholesterol can prevent strokes that would otherwise occur severalyears later, Salcor encourages Garnet employees to have their cholesterollevels tested and to obtain early treatment for high cholesterol.  Renco employees generally remain with Rencoonly for a few years, however. Therefore, Salcor lacks any financial incentive to provide similar encouragementto Renco employees.
Which of thefollowing, if true, most seriously weakens the argument?
A. Early treatmentof high cholesterol does not eliminate the possibility of a stroke later inlife.
B. People oftenobtain early treatment for high cholesterol on their own.
C. Garnet hires asignificant number of former employees of Renco.
D. Renco and Garnethave approximately the same number of employees.
E. Renco employeesare not, on average, significantly younger than Garnet employees.
答案是C为什么呀？

hartmann

不知道这么说对不对：

这题有一个必要条件。没这个条件，结论不成立。

这个条件就是：医生是先给员工治疗，几年后再向雇主收费，但如果员工离开了，雇主将不再承担费用。

因为Renco员工做不长，因此如果提前做了治疗，后来员工走了，而且雇主也不再承担还未支付的医疗费，医生将没有收入。因此，给Renco员工做治疗，缺少financial incentive。

C正确，因为Renco 走了的员工来到了Garnet，Garnet 将继续为他们支付医疗费用。