In order to increase its profits, an Italian restaurant in Pastanton placed its advertisement in one of the local newspapers. After several months, the restaurant's management noticed that the number of customers had increased only slightly, and most of them had never seen the advertisement. Therefore, the management proposed to discontinue placing its advertisement in that newspaper.

Knowing which of the following would LEAST help to evaluate the proposal of the restaurant's management?

A. Whether the circulation of the newspaper is expected to increase any time soon.
B. Whether most new customers who came to the restaurant after seeing its advertisement in the newspaper generally made large orders that generated significant profits to the restaurant.
C. Whether most new customers who came to the restaurant after seeing its advertisement in the newspaper were satisfied with the quality of service in the restaurant.
D. Whether there are alternative ways to advertise the restaurant that would cost the same as placing the advertise in the newspaper but would generate more profits to the restaurant.
E. Whether the cost of the advertisement exceeds additional profits gained on customers who came to the restaurant after seeing the advertisement.

OA is C
Can an Expert explain this to me in details. Contributions will be highly appreciated. Thanks