OG11-58 紫皮

A recording system was so secretly installed and operated in the Kennedy Oval Office that even Theodore 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
(C) It was so secret that a recording system was installed and operated in the Kennedy Oval Office
(D) A recording system that was so secretly installed and operated in the Kennedy Oval Office
(E) Installed and operated so secretly in the Kennedy Oval Office was a recording system that

选A

A选线中的so secretly 能不能放在operated的后面？E为什么不对呢？是倒装啊