In Recent Years New Automobile Factories Have Opened in California

Multiple Choice

In recent years new automobile factories have opened in California and Ohio and closed in Detroit where the unemployment of automobile workers has increased.This unemployment could be decreased if

A) "moving costs" from Detroit to California and Ohio were reduced.
B) information about the new jobs was made available to the unemployed workers at reduced cost.
C) workers with the appropriate skills were relatively scarce in Ohio and California.
D) all of the above.