补充250-40 请教

40.   The average weekly wage nearly doubled in the 1970’s, rising from $114 to $220, yet the average worker ended the decade with a decrease in what their pay may buy.

(A) with a decrease in what their pay may buy

(B) with what was a decrease in what they were able to buy

(C) having decreased that which they could buy

(D) decreasing in purchasing power

(E) with a decrease in purchasing power

答案是E，请问这里with 的用法是什么？