求教一道LR,thx

This summer,Jennifer,who has worked at KVZ Manufacturing for just over three years,plans to spend with her family the entire four weeks of paid vacation to which she is entitled this year. Anyone one who has worked at KVZ Manufactureing for betrween one and four years is automatically entitled to exactly three weeks paid vacation each year but can apply up to half of any vacation time that remains unused at the end of one year to the next year's vacation.

If the statements above are all true,which one of the following must also be true on the basis of them?

A)Jennifier did not use two weeks of the paid vaction time to which she was entitled last year.

B)If Jennifer continues to work for KVZ Manufacuring, she will only be entitled to three weeks paid vaction next year.

D)Last year Jennifer took only one week of the paid vacation time to which she was entitled.

A is correct.

why A? I think for A to be correct,it should add" at least" two weeks.Because there is "up to half" in the stimulus.

题目本身说她得到的这四周【3周应有的+1周（以前剩下的一半）】中，并没表示她已经把原来积累的假期全部用完了啊。这个at least不加一样不表示她没用完的假期只有2周啊。。。和up to half 结合起来看看。at least还是不用加吧，加了的话更科学一些。但是不加的话在逻辑上一样的没有问题