A recording system was so secretly installed and operated in the Kennedy Oval Office that even Theodoce C.Sorensen, the White House counsel, did not know it existed.

(A)A recording system was so secretly installed and operated in the Kennedy Oval Office that

(B) So secret was a recording system installation and operation in the Kennedy Oval Office that

(C) It was so secret that a recoring system was installed and operated in the Kenney Oval Office

(D) A recoring system that was so secretly installed and operated in the Kenney Oval Office

(E) Installed and operated so secretly in the Kenney Oval Office was a recoring system that

答案是A，我想问一下E为什么错？

“so+副词”置于句首以示强调时，其后的主谓作部分倒装。
如: So loudly did he speak that even the people in the next room could hear him.