​Retailers do not find it profitable to engage in promotional activities because

A) ​They reap the full benefits of the promotion
B) They do not have to share the benefits of the promotion with the manufacturer
C) They are wary of competing retailers' ability to "free ride" on their efforts
D) ​All of the above

Retailers may not find it profitable to engage in promotional activities because they are concerned that competing retailers might benefit from their efforts without contributing any resources to the promotion. As a result, they may be reluctant to invest in promotional activities. The other choices are not accurate as retailers typically share some of the promotional benefits with the manufacturer and engage in promotional activities to boost sales and profits.