一道LR题，各位高手帮忙解答下哈

Whenever she considers voting in an election to select one candidate for a position and there is at least one issue important to her, Kay uses the following principle in choosing which course of action to take: it is acceptable for me to vote for a candidate whose opinions differ from mine on at least one issue important to me whenever I disagree with each of the other candidates on even more such issues; it is otherwise unacceptable to vote for that candidate. In the upcoming mayoral election, the three candidates are Legrand, Medina, and Norton. There is only one issue important to Kay, and only Medina shares her opinion on that issue. 

    

According to the principle stated in the passage, in the upcoming mayoral election

(A) it is acceptable for Kay to vote for either Medina or Legrand, but it is unacceptable for her to vote for Norton.

(B) the only unacceptable coursed of action are for Kay to vote for any of the candidates.

(C) it is unacceptable for Kay to vote for any of the candidates.

(D) the only unacceptable course of action is for Kay to vote for Medina.

(E) it is acceptable for Kay to vote for any of the candidates.

B   C  的区别是什么呢，我实在搞不清楚。。。。。。

答案是B

好像没有吧。。。。我又看了遍