Which of the Following Factors Are Likely to Lead to an Increase

Which of the following factors are likely to lead to an increase in the female/male earnings ratio in the future?

A) As the labor force participation of women increases, their years of work experience will become more similar to men.
B) In recent years, a higher proportion of women have been preparing for careers in the professions.
C) As the proportion of families headed by a female parent increases, the average hours worked per week of female employees will decline.
D) Both a and b are correct.