Wage difference that can't be explained by the number of years of training, are likely to be considered to

Question

Wage difference that can't be explained by the number of years of training, are likely to be considered to result from factors associated with
a) demand, but not supply
b) supply, but not deman
c) conditions of regulated markets
d) compensating differentials

Answer 1

This seems to be a test question, and all answers could suffice, although:
a) and b) seem to be contradictory in themselves; demand alone and supply alone do not determine the wage.
Also, conditions in regulated markets would indicate some presence of unions.
Finally, compensating differentials will only apply to jobs that are not homogenous.

Answer 2

Factors in the market place. All of the above.