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?
The premise is that 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.
then, the argument concludes that since the percentage of the Kravonian workforce with college degrees will increase dramatically, the average salary for all workers in Kravonia is likely to increase.
So, it should rule out the possibility that "The average salary in Kravonia for jobs that do not require a college degree will not increase over the next four years", so that it can properly draw the conclusion that the increase of the average salary is due to the increase of people with college degrees.