语法大全845，补充186

1.     The utility company has announcedthat it will permanently close its Unit I nuclear power plant, the first plant thathad been built by private industry and the model for a generation of modernnuclear reactors.

(A) that had beenbuilt by private industry and

(B) built byprivate industry and which was

(C) to be built byprivate industry and which was

(D) built byprivate industry and（D）

(E) to have beenbuilt by private industry and was

答案是D，求助A为什么不可以，我的理解是built是在announed之前发生的动作所以用过去完成时应该也可以

看语法大全解析说d的and并列结构更好，d比a好在哪里呀？