OG 136 help

请教NN们: 为什么C不对? 可否这样理解: 主句主干是: so... as to...; 同时因为so...提前, 句子倒装.

正确答案是A.  (但是OG 在解释选项C时, 极其简略, 偶不能信服).

1.        Although schistosomiasis is not often fatal, it is so debilitating that it has become an economic drain on many developing countries.

(A) it is so debilitating that it has become an economic

(B) it is of such debilitation, it has become an economical

(C) so debilitating is it as to become an economic

(D) such is its debilitation, it becomes an economical（A）

(E) there is so much debilitation that it has become an economical

没具体看，不过感觉as to become an economic....很别扭

还有一个，倒装的位置，察看一下，印象中有的倒装要求在句子开头

纯属感觉，你在自己看看