Read this excerpt from a passage.

"Not only are students’ reading choices sometimes censored, so are their clothing choices. Many schools have a mandatory uniform or a dress code for students. These policies are said to promote safety and discipline. However, they also limit how students can express themselves through their appearance. According to the National Center for Education Statistics, in the past decade the number of public schools requiring students to wear uniforms has almost doubled, to 19 percent (Abutaleb, 2012). Although some students and parents welcome uniforms and dress codes, others do not. In 2001, a group of students and parents in Texas took a school district to court contending that the school’s mandatory uniform policy violated First Amendment rights. The Fifth Circuit Court ruled that the school’s policy was constitutional and that students had failed to show that the policy suppressed free expression. In cases involving school dress codes, courts across the country have generally upheld school policies. But some school dress codes seem unnecessarily restrictive. There are dress codes that forbid sandals, flip-flops, fuzzy slippers, boots, leggings, and clothes with the names of sports teams. Whenever a dress code or uniform is enforced, it can be argued that the right of students to express themselves is suppressed."

Which supporting detail best supports the main idea?