大全SECTIONC-17，是排除了他因么？
17. In a marketing study, consumers were given two unlabeled cartons of laundry detergent. One carton was bright green and yellow; the other was drab brown and gray. After using the detergent in the two cartons for one month, 83 percent of the consumers in the study reported that the detergent in the bright green and yellow carton cleaned better. This study shows that packaging has a significant impact on consumers’ judgment of the effectiveness of a laundry detergent.
Which of the following, if true, would most strengthen the conclusion drawn in the marketing study?
(A) The detergent in the bright carton contained bleach crystals; the detergent in the drab carton did not.
(B) The detergents in the two cartons were the same.消费者认为是PACAKING影响清洁剂，只要说清洁剂是一样就OK，排除了其他原因导致两个carton的清洁剂质量不同
(C) The detergents in the two cartons were different, but they had both been laboratory tested. C===B
(D) The detergent in the drab carton was a popular name brand; the detergent in the bright carton was generic.（B）
(E) The detergent in the drab carton was generic; the detergent in the bright carton was a popular name brand.
这里选B，是排除了其他原因导致两个carton的清洁剂质量不同：前者比后者好？
我发现逻辑很多题目，选项正确的都是选那种什么与什么都一样的。 | 
