Which of the Following Is True of Self-Liquidating Premiums

Which of the following is true of self-liquidating premiums?

A) They are used for lightweight, nonperishable products.
B) They require customers to pay for the mailing costs.
C) They are typically offered at higher-than-retail prices.
D) They are also known as cost-plus premiums.
E) They are usually delivered directly to the customers' doorsteps.