Mystery Shoppers Are People

Mystery shoppers are people

A) hired by a firm to get legal,though not necessarily ethical,information about competitive firms.
B) hired by a firm's employees to prove to the courts that competitors are using unfair pricing practices.
C) hired by a customer to report on illegal or unethical practices that are regularly taking place at a particular establishment.
D) who pose as customers to check on a firm's products or services and are paid to write a detailed report on their experiences.
E) hired by law firms to check on the safety of their clients' products.