[求助]but instead用法

请问牛牛们，but instead是正确用法吗？

我发现GWD里面好像都是错的，但是，昨天我做GMATprep有一题的正确答案就是选的but instead.

到底but instead怎么用，什么意思呢？

73.   (28457-!-item-!-188;#058&003634)

Evolutionary psychology holds that the human mind is not a "blank slate," but instead that it comprises specialized mental mechanisms that were developed as a way of solving specific problems human ancestors faced millions of years ago.

(A) the human mind is not a "blank slate," but instead that it comprises specialized mental mechanisms that were developed as a way of solving

(B) the human mind is not a "blank slate" but instead comprises specialized mental mechanisms that were developed to solve

(C) the human mind, instead of a "blank slate," it comprises specialized mental mechanisms that have been developed to solve

(D) rather than it being a "blank slate," the human mind comprises specialized mental mechanisms that have been developed as a way of solving

(E) rather than the human mind's being a "blank slate," that it comprises specialized mental mechanisms that were developed as a way of solving

原题， 答案选B