A of (B and C) that的指代－－987-987新问

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

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

答案是C

但是偶有个问题，a consistency of quality and production that was 中的that，指的是consistency是吗？为什么没有指向production的歧义呢？

或者，A of (B and C) that没有任何可能指代C,甚或B+C,仅仅可能指代A吗?

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