T-4-Q34 pls help

T-4-Q34

In Kravonia, the average salary for jobs requiring a college degree has always been higher than the average salary for jobs that do not require a degree. Current enrollments in Kravonia’s colleges indicate that over the next four years the percentage of the Kravonian workforce with college degree will increase dramatically. Therefore, the average salary for all workers in Kravonia is likely to increase over the next four years.

Which of the following is an assumption on which the argument depends?

1. Kravonians with more than one college degree earn more, on average, than do Kravonians with only one college degree.

2. The percentage of Kravonians who attend college in order to earn higher salaries is higher now than it was several years ago.

3. The higher average salary for jobs requiring a college degree is not due largely to a scarcity among the Kravonian workforce of people with a college degree.

4. The average salary in Kravonia for jobs that do not require a college degree will not increase over the next four years.

5. Few members of the Kravonian workforce earned their degrees in other countries.

I donot understand why C is the key?  My key is D.

这题我洗了个澡时想明白了。唉，把题义想当然的想偏了。

看来，我要上700，还得看当天的状况

我也有同样的问题,为了避免重复发帖,能不能把你洗澡的大悟讲一下,谢谢了

否则的话,我看我就得一直洗澡了

在C和D中，我认为C的选项是说高学历人中的高工资的给出不是因为缺少高学历人导致的。

那么去过取非就是说高学历的高工作的给出是因为高学历人少，那么4年来比例增加，高学历人多了，工资就应该下降啦。。

D中说了那些不需要高学历的工种的工资在这4年里没有增加。

那么取非就是那些低学历的工种的工资增加了，而且高学历的人也是一向比他们的工资高，所以平均工资应该更高啊？同意了原文的观点，所以不对。。