1. With diamonds, as with all gems, one should ask for a written description of one’s purchase; the description may prove useful later if you have reason to believe the jeweler misled you.

(A) one should ask for a written description of one’s purchase

(B) you should ask for a written description of your purchase

(C) a written discretion of your purchase is what one should ask for

(D) a written description of one’s purchase is what should be asked for（B）

(E) a written description of your purchase is what should be asked for

不是说you是口语化的表达方法，是属于corrective的错误吗？我刚看到这题时就是因为这个原因才马上否定b的

主要是因为后面用了you, 所以前后要一致.

the description may prove useful later if you have reason to believe the jeweler misled you.