新手弱问：og11的diagnostic test中的一道critical reasoning不解

广告总收入主要由两部分组成：1.单份杂志的广告收入；2.杂志的销量。

作如下假设：2000年的单份收入是10美元，销量是10万份，则该年广告总收入为100万美元。假如2002年广告总收入为200万美元，而该年的销

量仍然是10万份，，则单份收入变成20美元，这说明广告业务员的业绩提高了（PS.广告业务员与杂志业务员是两个概念）。再假如2002年广告

总收入为200万美元，而该年的销售量为20万份，则单份杂志的广告收入还是10美元，这说明广告业务员的业绩没有提高。

结论：总收入增加，销量基本不变，则广告业务增加，改革有效；总收入增加，销量也显著增加，则广告业务基本不变，改革不怎么有效。

不知道我说清楚了没有？

我想请问一下，

Following several years of declining advertising sales, the Greenville Times reorganized its advertising sales force. Before reorganization, the sales force was organizes geographically, with some sales repersentatives concentrating on city-center businesses and other concentrating an different outlying regions. The reorganization attempted to increase the sales representatives' knowledge of clients' businesses by having each sales representative deal with only one type of industry or of retailing. After the reorganization, revenue from advertising sales increased.

In assessing whether the improvement in advertising sales can properly be attributed to the reorganization, it would be the most helpful to find out which of the following ?

B   Has the circulation of the Greenville Times increased substantially in the last two years?

E   Among the advertisers in the Greenville Times,  are there more types of retail business or more types of industrial business?

此题的E选项不能作为评估吗？题目中不是正说业务员每人负责一个retail或industrial的项目吗？如果增多了，不能表示重组有效吗？如果减少了，就是无效啊？

请问哪里理解错了？