GMAT选项中是否会出现多余的词？

lunachasedream

《语法大全》中看到以下两道题~

During the recession of 1973,home mortgage foreclosures resulted in tens of thousands of Americans beingevicted from homes that they can no longer afford monthly payments.

(A) that they can

(B) that theycould

(C) on which theycan

(D) because theycan（E）

(E) for which theycould

我选了B，正确答案说是E。因为B选项中的that多余。我想说这边的that不作成分，是可加可不加的，是不是GMAT选项中的词是能省就省，能省不省就算错？
另外类似的还有下面这道

For protection from the summersun, the Mojave lived in open-sided, flat-topped dwellings known as shades, eacha roof of poles and arrowweed supported by posts set in a rectangle.

(A) each a roof ofpoles and arrowweed

(B) each a roof ofpoles and arrowweed that are being

(C) with eachbeing a roof of poles and arrowweed

(D) with roofs ofpoles and arrowweed to be（A）

(E) with roofs ofpoles and arrowweed that are

我选了E，正确答案是A。也说是因为E中that are可以省，这边没省就算错！