Which of the Following Is an Example of a Trade

Which of the following is an example of a trade promotion?

A) A magazine carries a shampoo sachet as a sample for customers to try out before buying more of the product.
B) A restaurant sends its customers a direct mail about food festivals and discounted meals that they can avail at the restaurant.
C) A newspaper carries freestanding inserts about discounts customers can avail at a movie theatre.
D) A clothing brand provides consumers coupons with which they can avail a discount on the woolen line of clothing.
E) A manufacturer offers a department store a buyback allowance for a line of cosmetic products that it hasn't sold.