求助一道逻辑题 非常感谢

The president of a consulting firm analyzed the decisions made about marketing by her clients and concluded that the decisions were correct only half of the time.The conclusion above depends on presupposition that

A.companies can be successful even when about half of the decisions the make about marketing prove to be wrong.

B.companies hiring her consulting firm make no more incorrect marketing decisions than do companies in general

C.executives consistently making correct marketing decisions rarely enlist the aid of a consulting firm

D.marketing decisions are just as likely to be correct as they are to be incorrect

E.it is possible to classify a marketing decision properly as being either right or weong 

why we should choose E .thank you for helping

E中的明确分类说明了只有对和错的可能，所以对的机会是50％

其他都很不相关。最接近的是D，但是D只是说对的跟错的数目一样，并不能说明对的可能是多少。针对的东西不同

e