The correct answer to this is C. Only favorable information is likely to appear. Of course, advertising a product entails wooing potential buyers to actually buy the product. That is why only positive feedbacks can be seen when people see advertisements from a reliable person most likely to gain the trust of the viewers. Celebrities, doctors, scientist are paid to say something nice about the product so that people will be enticed at buying it. This is not a reliable way to look for honest reviews.
Advertising is NOT a good way to find harmful information about a product because a. it is not endorsed by the government. b. there are no regulations to control what is said. c. only favorable information is likely to appear. d. it is the most available source of information.