Over the past half-century, the "labor force participation rates of women" (the proportion of women who work) has increased relative to those of men. At least two factors have influenced the increase in labor force participation by women. First, most middle-income families realize that it takes two workers to live comfortably. In addition, except among the wealthy, staying at home is no longer held in high regard. For many reasons, women want to have careers equal to men.
Which of the following helps explain why such a large proportion of women work outside of the home?

A. Families who wish to live middle class lives find that it generally takes two paid workers to live comfortably.
B. The government pays for good childcare for all working women.
C. Few women find it rewarding to have a career.
D. Fewer women than men now get college degrees.