Answer:
The correct answer is A. The advertiser.
Step-by-step explanation:
When a celebrity is endorsing a product, only the advertiser is liable for false or unsubstantiated claims made about the product. This is so because it is the advertiser, that is, the company that produces the product to be advertised, who hires the celebrity to carry out the advertising and, in addition, is solely responsible for the characteristics of the product that is being marketed. Ultimately, the celebrity is a simple "employee" in the advertising process, hired by the advertiser to carry out his tasks in exchange for remuneration.