OG-19中的一句解释看不懂

steve66

19.
            In addition to having more protein than wheat does, the protein in rice is higher quality than that in wheat, with more of the amino acids essential to the human diet.

(A) the protein in rice is higher quality than that in

(B) rice has protein of higher quality than that in

(C) the protein in rice is higher in quality than it is in

(D) rice protein is higher in quality than it is in

(E) rice has a protein higher in quality than

choices A, C, and D illogically compare wheat with protein and claim that the protein in rice has more protein than wheat does. In C and D, the comparative structure higher in quality than it is in wheat absurdly suggests that rice protein contains wheat.

明白ACD的共同点是比较主体错误，可是不明白为什么解释中又加了一句，In C and D, the comparative structure higher in quality than it is in wheat absurdly suggests that rice protein contains wheat.

这句话好像在说假如CD的比较主体正确的话，另外还有一个是由比较结构导致的错误，是CD有而A所没有的错误，就是suggests rice protein contains wheat，我怎么也看不出这是怎么样理解出来的，请各位同学帮忙解答一下；

yangby03

C和D的比较结果荒谬地体现出了蛋白质包含了小麦

steve66

对不起，我的表达不大清楚，我想问的是，如何理解出有这一层意思呢？比方说C吧，带入到句子中，

In addition to having more protein than wheat does, the protein in rice is higher in quality than it is in wheat, with more of the amino acids essential to the human diet.

在我看来，只有一个错误就是the protein in rice错了，与前面的having more protein意思不搭配，可是解释中说除此之外，比较结构也有错误，因为它会使人误解为protein contains wheat，就从上面这个句子来看，怎么会有这个误解呢？

yangby03

介词+动词ing形式的结构中，逻辑主语（动作的发出者）=主句主语