请教一道LAST逻辑题

憧憬

A linguist rencently argued that all human languages must have a common origin because some concepts are universal ;that is they appear in all languages .For example,all languages are capable of describing lightness and darkness.
Which one of the following ,if ture would most seriouly weaken the argument?
(A) The Bernese language does not contain basic nouns like automobile and airplane.
(B) No one linguist could possibly speak all known languages.
(C)All speakers ,regardless of their languages are confronted with similar stimuli like lightness and darkness.,
(D)The similarity between human language and dolphin language has not been attributed to a common origin.
(E)Some languages include concepts of which speakers of other languages are not even aware.
答案是第二个。为什么？
Unless Elizabeth goes I must go .But she will not go if I stay .So we will both have to go.请问这是怎么推出来的

番茄炒蛋

前面一题的答案我怎么记得是C啊？
后面这个逻辑也没有想通
草莓呢？他肯定可以解释的

睡熊

上面一题的答案的确是C;

后面一个: I stay => Elizabeth goes;
              I stay => Elizabeth stays

所以通过以上关系推不出 So we will both have to go, 倒是能推出：I will have to go whatever Elizabeth goes or not.