系统解析:第一段第一、二句“ When Bill de Blasio ran for New York City mayor last year, he promised to end a controversial , city wide cell-phone ban in public schools, which is not equally enforced in all schools. Now, under his leadership, the city is preparing to end the ban.”。主旨大意题。题干问的是“下列哪一个是文章的主旨?”根据定位句“当比尔竞选纽约市长的最后一年,他承诺要结束一个有争议的、范围广的公立学校手机禁令,这并不是在所有的学校同样执行。现在,在他的领导下,该市正准备结束这个禁令”。故选 D。