618．School integration plans that involve busing between suburban and central-city areas have contributed, according to a recent study, to significant increases in housing integration, which, in turn, reduces any future need for busing.

(A) significant increases in housing integration, which, in turn, reduces

(B) significant integration increases in housing, which, in turn, reduces

(C) increase housing integration significantly, which, in turn, reduces

(D) increase housing integration significantly, in turn reducing（A）

(E) significantly increase housing integration, which, in turn, reduce

A的WHICH是指代housing integration吗??

是的，以前的贴子说过

School integration plans that involve busing between suburban and central-city areas 这句已经给了提示，是integration本身带来各种好处，而不是多少的变化。