求助一道逻辑题的答案和解题思路

TT3

Q19:

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 degrees 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?

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

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

C.   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.

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

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

   Answer:

答案为什么是C呢？是不是错了啊？

谢谢大家~

C应该没问题。

稀缺性的问题哈，如果大学生工资高时因为大学生供不应求的原因造成的，那么在大学生数量增加以后，大学生的工资就可能会降低，城市的平均工资也就不一定会增高了。