Which of the Following Is Not a Reason to Explain

Which of the following is not a reason to explain the persistence of the earnings gap between men and women?

A) Women are concentrated in lower-paying occupations.
B) Women are less efficient at their jobs because, as a rule, they assume additional responsibilities of caring for home and family.
C) Women enter the labor force at different and lower-paying levels than do men.
D) Women as a group have less education and experience than do men; therefore, they are paid less than men.