请教一道大全ＣＲ题目，我怎么觉得前提结论分不清楚呀？

23.   No computer will ever be able to do everything that some human minds can do, for there are some problems that cannot be solved by following any set of mechanically applicable rules. Yet computers can only solve problems by following some set of mechanically applicable rules.

Which one of the following is an assumption on which the argument depends?

(A) At least one problem solvable by following some set of mechanically applicable rules is not solvable by any human mind.

(B) At least one problem not solvable by following any set of mechanically applicable rules is solvable by at least one human mind.

(C) At least one problem solvable by following some set of mechanically applicable rules is solvable by every human mind.

(D) Every problem that is solvable by following more than one set of mechanically applicable rules is solvable by almost every human mind.（B）

(E) Every problem that is solvable by following at least one set of mechanically applicable rules is solvable by at least one human mind.

答案是Ｂ，　请教这道题为什么不选择Ａ呀？

我怎么搞不清楚这道题目的前提和结论了。

请ＮＮ指点

A说的是"至少有一题是人脑解决不了的,而这题能机械推导"

而题目是说"电脑只能机械推导,人脑比电脑强". 所以A中说的"一题",一定能被电脑解决,undermine原推论.

故assumption必定是类似"至少有一题人脑能解决,电脑半不到"的话.正如B所说.