[求助]大全646

1.        Since 1986 enrollments of African Americans, American Indians, and Hispanic Americans in fulltime engineering programs in the United States has steadily increased, while the number of other students who enter the field has fallen.

(A) has steadily increased, while the number of other students who enter the field has fallen

(B) has steadily increased, while other students entering the field have declined in number

(C) increased steadily, while there was a decline in the number of other students entering the field

(D) have steadily increased, while the number of other students entering the field has fallen（D）

(E) have steadily increased, while that of other students who enter the field fell

D如果改成while the number of other students who enter the field has fallen对不对啊？限制性定语从句和非限制性定语从句在这句中有什么区别吗？

记得又到题也牵涉到这里的内容

这里while是连词，enrollment和the number of概念虽不对等，但是不影响这里的答案。