987 With cloning technology, scientists are approaching what has long been the ultimate goal of modern husbandry: achieving a consistency of quality and production in farm animals as once thought to be limited to manufactured goods.

(A) achieving a consistency of quality and production in farm animals as once thought to be

(B) achieving farm animals with a consistency of quality and production as were once thought of as

(C) achieving in farm animals a consistency of quality and production that was once thought to be

(D) achievement of farm animals whose consistency of quality and production are the same as what were once thought to he（C）

(E) achievement of farm animals at a consistency of quality and production once thought of as

请教为什么选C,我怎么觉得那个THAT 容易造成歧义呢?THAT 好像既可以修饰CONSISTENCY,也可以修饰整个AHIEVING 的过程(当然这种修饰是错的).请指教A为什么错?谢谢!!