In 1988 unemployment in some regions of the United States dropped to the lowest rate in ten years, while the rate in other regions reached an all-time high. In 1978 similar conditions led to large migrations of workers from regions with high unemployment to regions with low unemployment. There was, however, significantly less such migration in 1988.
Premise 1988 : Some regions low unemployment rate ....some regions high unemployment rate.
1978: Large migration from High unemployment region to Low unemployment region
So
Migration in 1978 >Migration in 1988...Why?
Which of the following, if true about 1988, would contribute most to explaining why there was less migration of workers in 1988 ?
(A) The regions with the lowest unemployment rates had many of the same kinds of industries as those in the regions with high unemployment, but this was not the case in 1978.
-->Incorrect: So what if the same kinds of industries existed in both regions(low unemployment and high unemployment)? It does not explain the 'less migration'. Even if you had same industries what if the employability of the industries in these regions were different. We do not know anything about this.
(B) In contrast to 1978, the regions with the lowest unemployment rates had the largest number of new jobs, although substantially fewer of the new jobs required retraining.
-->Incorrect: Then why would there be lesser migration in contrast to that of 1978? This would weaken the argument.
(C)
In contrast to 1978, housing costs in the areas with the lowest unemployment rates were substantially higher than housing costs in other parts of the country.-->
Correct: Interesting. We are given a potential reason to why there was less migration to the regions of lower unemployment. What if the housing costs were higher? What if your property rent was an exorbitant amount and you were still employed in that region but received a low wage? Keep (C).
(D) The unemployment rate in countries outside of the United States was higher than it was ten years before.
--> Incorrect: We are not at all concerned about the unemployment rate outside of the U.S. Moreover, the premise does not establish any connection to the world outside the U.S.
(E) Unemployment benefits in the regions of high unemployment were slightly lower than they were ten years earlier in regions of high unemployment.
--> Incorrect: Then why was there less migration? This statement does not strengthen the argument rather weakens it in a way.
An: (C).