Firms Pay Famous Individuals to Endorse Their Products Because

Firms pay famous individuals to endorse their products because

A) apparently demand is affected not just by the number of people who use a product but also by the type of person that uses the product.
B) the firms are irrational and are wasting advertising expenditures.
C) famous people obviously know what are the best goods and services.
D) famous people only consume high-quality products.