In order to increase sales of its products, a company considered changing its advertising agency. To see whether the new advertising agency is capable of increasing sales, the company entrusted advertising of one product to the new agency. Over the next month, sales of this product increased by 10 percent; therefore, the new advertising agency is more capable of increasing sales than the agency currently advertising all the other products of the company.

Which of the following, if true, most weakens the conclusion of the argument above?

(A)
Since the new agency used the same magazines and radio stations for advertising, the total cost of advertisements did not change.
(B)
The company will only become profitable if it increases sales of all its products by at least 20 percent.
(C)
Over the same period, sales of the company’s products advertised by the old agency also increased by at least 10 percent.
(D)
Although the company considered that in order to increased sales the target group for the advertisement should be changed, the new advertising agency did not change the ad’s targeting.
(E)
Increasingly large numbers of consumers no longer believe advertisements and are not likely to change their purchasing habits after seeing an advertisement.

gogmat

Are you agree with the official answer?
can we conclude anything based on % only?w/o any information given about the base for the %

(A) Since the new agency used the same magazines and radio stations for advertising, the total cost of advertisements did not change. - Out of scope - Irrelevant - Incorrect
(B) The company will only become profitable if it increases sales of all its products by at least 20 percent. - Irrelevant - Takes a neutral stand over the conclusion - Incorrect
(C) Over the same period, sales of the company’s products advertised by the old agency also increased by at least 10 percent. - Since the products advertised by old agency had a max sales increase of 10%, it implies that old and new agencies are tied - Correct
(D) Although the company considered that in order to increased sales the target group for the advertisement should be changed, the new advertising agency did not change the ad’s targeting. - Strengthens - Incorrect
(E) Increasingly large numbers of consumers no longer believe advertisements and are not likely to change their purchasing habits after seeing an advertisement. - Irrelevant information - Incorrect