[求助]XDF new book——341

向大家请教一道新东方新版蓝皮书上的逻辑题目，题号标为341，请大家帮我解释下应该怎么理解，非常感谢！

341.

When people predict that certain result will not take place unless a
certain action is taken, they believe that they have learned that the
prediction is correct when the action is taken and the result occurs.
On reflection, however, it often becomes clear that the result admits
of more than one interpretation.
Which of the following, if true, best supports the claims above?

(A) Judging the success of an action requires specifying the goal of
the action.
(B) Judging which action to take after a prediction is made requires
knowing about other actions that have been successful in similar past
situations.
(C) Learning whether a certain predictive strategy is good requires
knowing the result using that strategy through several trials.
(D) Distinguishing a correct prediction and effective action from an
incorrect prediction and ineffective action is often impossible.
(E) Making a successful prediction requires knowing the facts about the
context of that prediction

unless是if not的意思 那When people predict that certain result will not take place unless a certain action is taken是指 不采取某种行动会推出某种结果的不发生，逆否下的话就是 某种结果的发生可以推出采取了某种行动？也就是说某种结果发生应该是某种行动采取的充分条件。那原题我理解为 当人们预测 某种结果的发生可以推出采取了某种行动（也就是某种结果的发生是由于某种行动的采取）时， 他们已经了解到当行动采取同时结果发生时，预测是正确的。 经过思考，然而，某种结果的发生是可能有不同的原因。

这样理解对吗？

unless是if not的意思 那When people predict that certain result will not take place unless a certain action is taken是指 不采取某种行动会推出某种结果的不发生，逆否下的话就是 某种结果的发生可以推出采取了某种行动？也就是说某种结果发生应该是某种行动采取的充分条件。那原题我理解为 当人们预测 某种结果的发生可以推出采取了某种行动（也就是某种结果的发生是由于某种行动的采取）时， 他们已经了解到当行动采取同时结果发生时，预测是正确的。 经过思考，然而，某种结果的发生是可能有不同的原因。

这样理解对吗？

我还是不大理解你的inferrence结果的对错 实际上 是很难判断的,这个inference是从“但是 结果 可以被解释成很多种”引申出来？

我是理解成你分析的否命题和你否命题的差异就是题目的那个转折的前后意思。会不会是说人们习惯上用的否命题来作为标准 而事实上逻辑上应该是逆否命题作为标准，因而产生了差异，从而说明无法评价预测正确性？