和og-199相同的题干,不同的选项,求答案

Vitacorp, a manufacturer, wishes to make its information booth at an industry convention more productive in terms of boosting sales. The booth offers information introducing the company’s new products and services. To achieve the desired result, Vitacorp’s marketing department will attempt to attract more people to the boost. The marketing director’s first measure was to instruct each salesperson to call his or her five best customers and personally invite them to visit the boost.

Which of the following, if true, most seriously weaken the predication that the marketing director’s first measure will contribute to meeting that goal of boosting sales?

A.    Customers who participate booth are those not satisfied with Vitacorp products and will use this opportunity to express their unsatisfaction.

B.    Many of Vitacorp’s competitors have made plans for making their own information booths more productive in increasing sales.

C.    An information booth that is well attended tends to attract visitors who would not otherwise have attended the booth.

D.    Most of Vitacorp’s best customers also have business dealings with Vitacorp’s competitors.

E.    Vitacorp has fewer new products and services available this year than it had in previous years.

我的选择C, 请问确切的答案

gwd-21里的一道题，但是C是support不是weaken

如果是weaken 应该选A