Which of the following statements is true?

For the first time in a generation, public schools have won broad freedom to teach boys and girls separately, stirring a new debate about equality in the classroom. The Education Department on Tuesday announced rules that will make it easier to create single-sex classes or schools, a plan that’s been expected for almost three years. The move comes as the value of same-sex education is in doubt. Research shows mixed results, as even the department’s own review says. Yet Education Secretary Margaret Spellings said more parents deserve to have the option. The push began not with the White House, but rather with female senators of both parties. "Research shows that some students may learn better in single-sex education environments," Spellings said, careful not to offer an outright endorsement. "The Department of Education is committed to giving communities more choices in how they go about offering varied learning environments," she said. The new federal rules may change how schools will look in the future.