OG12 CR Q104请教！！！

104.Although the discount stores in Goreville’s central shopping district are expected to close within five years as a result of competition from a SpendLess discount department store that just opened, those locations will not stay vacant for long. In the five years since the opening of Colson’s, a non-discount department store, a new store has opened at thelocation of every store in the shopping district that closed because it could not compete with Colson’s.

Which of the following, if true, most seriously weakens the argument?

(A) Many customers of Colson’s are expected to do less shopping there than they did before the SpendLess store opened.

(B) Increasingly, the stores that have opened in the central shopping district since Colson’s opened have been discount stores. B

(C) At present, the central shopping district has as many stores operating in it as it ever had.

(D) Over the course of the next five years, it is expected that Goreville’s population will grow at a faster rate than it has for the past several decades.

(E) Many storesin the central shopping district sell types of merchandise that are not available at either SpendLess or Colson’s.

我找的conclusion是红字部分，但答案是B，我认为答案正好strength了这个conclusion。所以我想我是否把conclusion找错了？？
求大神解释！
谢谢