Answer: Testimonial advertising
Explanation:
If a company chooses a popular sports figure to advertise a product, the advertising method used by the company is referred to as testimonial advertising.
In testimonial advertising method, rather than a manufacturer coming to tell the customers or listeners about the product and its benefits, an end user of the product comes to radio station or is shown on television and helps in the advertisement of the product. In most cases, the end users are celebrities and they're used because people will want to purchase the product once they're aware that such celebrities are using such products thereby driving the sales and profit of the company.