大全-304，对大全解释which的疑惑

304.For many people, household labor remains demanding even if able to afford household appliances their grandparents would find a miracle.
(A) even if able to afford household appliances their grandparents would find a miracle
(B) despite being able to afford household appliances their grandparents would find a miracle
(C) even if they can afford household appliances their grandparents would have found miraculous
(D) although they could afford household appliances their grandparents would find miraculous
(E) even if they are able to afford household appliances which would have been a miracle to their grandparents

大全里面说E错在which只能修饰非限定性定语从句。我觉得从语法书里面好相差不到这点。这种说法是不是仅限于ETS prefer呢？

谢谢

印象中在GWD好像有例外, 这个不是什么定理.

E中的appliances和后面的a miracle单复不对应, can afford是习惯用法, 不能换成be able to.