feifei45,only if 的用法是这样理解么？

45. Commissioner: Budget forecasters project a revenue shortfall of a billion dollars in the coming fiscal year. Since there is no feasible way to increase the available funds, our only choice is to decrease expenditures. The plan before you outlines feasible cuts that would yield savings of a billion dollars over the coming fiscal year. We will be able to solve the problem we face, therefore, only if we adopt this plan. (应为if only吧？)

This reasoning in the commissioner’s argument is flawed because this argument

原句结论是：“be able to solve the problem we face”——> “adopt this plan"必要条件

(A) relies on information that is far from certain

(B) confuses being an adequate solution with being a required solution

如果答案为B的话，是否题目应为“adopt this plan"充分条件——>“be able to solve the problem we face”

(C) inappropriately relies on the opinions of experts

(D) inappropriately employs language that is vague

(E) takes for granted that there is no way to increase available funds

请指教：）

我的理解：

应为only if 因为后面接的是陈述语气 意思为“只要”

文中原意只要接受了这个计划 我们目前面临的问题就能解决了

但由therefore位置可知把充分条件当成了必要条件

请指正~~~

如果E改成takes for granted that there is no other way to increase available funds

是不是也可以选E了呢？