​Which of the following are ways of promoting a firm's product

A) ​Advertising
B) Discount coupons
C) End-of-aisle displays
D) ​All of the above

End-of-aisle Displays

Promotional merchandise displays located at the end of store aisles, designed to attract customer attention and increase product sales.

Discount Coupons

Promotional vouchers that reduce the price of goods or services, often used to attract customers or boost sales.