A. There is no significant difference among manufacturers of name-brand cereals in the prices they charge for their products.
--> store brand cereals are not even mentioned.
B. Consumers who have switched to store-brand cereals have generally been satisfied with the quality of those cereals.
--> consumers are satisfied with both the price and the qualify of store-brand cereals, so they are UNLIKELY to buy brand cereals.
C. Many consumers would never think of switching to store-brand cereals because they believe the name brand cereals to be of better quality.
--> the question states that "how to attrack back.....", the consumers mentioned in answer C did not use store-brand cereals at all.
D. Because of lower advertising costs, stores are able to offer their own brands of cereals at significantly lower prices than those charged for name-brand cereals.
--> 這個時間點不太明顯, 如果是在plan之前, D only tells us why store-brand cereals are cheaper. 如果是在plan之後, name-brand 的就很難再壓低價錢來挽回consumers.
E. Total annual sales of cereals—including both name-brand and store-brand cereals—have not increased significantly over the past five years.
--> E does not show any relationship between name-brand and store-brand cereals.