In the Same City,one Job Currently Pays $6 More Per

In the same city,one job currently pays $6 more per hour than another job.The two jobs have equivalent training requirements,but labor is not migrating toward the higher-paying occupation.Both markets are perfectly competitive.Which of the following conclusions is correct?

A) The lower-paying occupation has less attractive nonmonetary characteristics.
B) There are barriers to entry into the higher-paying occupation.
C) The higher-paying occupation has a dominant labor union.
D) There are barriers to entry into the lower-paying occupation.
E) The higher-paying occupation has less attractive nonmonetary characteristics.