单项选择题

Last week, The Washington Post ran a front-page story that said most stay-at-home morns aren’t S. U. V. — driving, daily yoga-doing, latte-drinking.upper-middle-class women who choose to leave their high-powered careers to answer the call to motherhood. Instead, they are disproportionately low-income, non-college educated, young and Hispanic or foreign-born: in other words, they are women whose horizons are greatly limited and for whom the cost of child care. very often, makes work not a workable choice at all.
These findings, drawn from a new report by the Census Bureau, really ought to lead us to reframe our public conversations about who mothers are and why they do what they do. It should lead us away from all the moralistic bombast about mothers’ "choices" and "priorities". It should get us thinking less about choice, in fact, and make us focus more on contingencies-the objective conditions that drive women’s lives. And they should propel us to think about the choices that we as a society must make to guarantee that the best possible opportunities are available for all families.
The basic finding of this latest report-that the more choices mothers have, the more likely they are to work-has been known, to anyone who’s taken the time to seriously look into the issue. Ever since 2003, when Lisa Belkin’s article in The Times magazine about highly privileged and ultra-high-achieving morns — "The Opt-Out Revolution" — was generalized by the news media to claim that mothers overall were choosing to leave the work force in droves, researchers have been revisiting the state of mothers’ employment and reaching very similar conclusions.
In 2007. the sociologists David Cotter, Paula England and Joan Hermsen looked carefully at four decades of employment data and found that women with choices-those with college educations-were overwhelmingly choosing to stay in the work force. The only women "opting out’in any significant numbers were the very richest-those with husbands earning more than $125, 000 a year-and the very poorest-those with husbands earning less than $ 23, 400 a year. You might say that the movement of the richest women out of the workforce proves that women will, in the best of all possible worlds, go home. But these women often have husbands who, in order to earn those top salaries, work 70 or 80 hours a week and travel extensively; someone has to be home. Many left high-powered careers that made similar demands on their time.
The alternative narrative-of constricted horizons, not choice-that might have emerged from recent research has never really made it into the mainstream. It just can’t, it seems, find a foothold.
"The reason we keep getting this narrative is that there is this deep cultural ambivalence about mothers’ employment." England told me this week. "On the one hand, people believe women should have equal opportunities, but on the other hand, we don’t envision men taking on more child care and housework and, unlike Europe, we don’t seem to be able to envision family-friendly work policies. "
Why this matters — and why opening this topic up for discussion is important — is very clear: because our public policy continues to rest upon a fictitious idea, eternally recycled in the media, of mothers’ free choices, and not upon the constraints that truly drive their behavior. "If journalism repeatedly frames the wrong problem, then the folks who make public policy may very well deliver the wrong solution. " is how E.J. Graff, the associate director and senior researcher at Brandeis University’s Schuster Institute for Investigative Journalism once put it in the Columbia Journalism Review. "If women are happily choosing to stay home with their babies, that’s a private decision. But it’s a public policy issue if schools, jobs and other American institutions arc structured in ways that make it frustratingly difficult, and sometimes impossible, for parents to manage both their jobs and family responsibilities. \
According to the passage, ______ is the root cause of women staying at home.