Practices Such as Misredeeming Coupons, Making Fraudulent Returns of Merchandise

Practices such as misredeeming coupons, making fraudulent returns of merchandise, filing warranty claims after the claim period, and so on are

A) acceptable provided the merchant providing the service has not violated the Consumer Bill of Rights.
B) acceptable provided the salesperson doesn't mind.
C) occasionally permitted when two different firms are competing for a customer's business and both are using equally less than ethical practices.
D) not acceptable because consumers also have an obligation to act ethically and responsibly.
E) not acceptable unless the participants are nonprofit organizations or charities.