638、sec07-24 Several years ago the diet industry introduced a variety of appetite suppressants, but some of these drugs caused stomach disorders severe enough to have them banned by the Food and Drug Administration.

(A) stomach disorders severe enough to have them

(B) stomach disorders that were severe enough so they were

(C) stomach disorders of such severity so as to be

(D) such severe stomach disorders that they were（D）

(E) such severe stomach disorders as to be

我的问题是：so as to用于简单结构，是指简单句吗？象这题的主从句是不是就不在这个范畴内，所以e才不对的？