Why Might Occupational Crowding Persist in Certain Industries,despite Educational Parity

Why might occupational crowding persist in certain industries,despite educational parity and an elimination of discrimination?

A) New forms of discrimination always emerge to suppress certain groups of individuals.
B) Wages are not high enough in other industries to attract those in more crowded occupations.
C) Colleges and universities usher gender and minority groups toward certain fields of study,perpetuating the crowding problem.
D) Workers don't view occupational crowding as a problem,preventing any incentive for mobility.
E) Personal preferences for certain types of jobs means that some groups will always have higher representation in those industries.