The answer to the question above is option C: they can result in a channel member having too much control. Firstly, we define what vertical system is. From the term itself vertical, the formation of the members is from top to bottom. Therefore, this includes the producer, wholesaler, and retailer and this is where the distribution channel occurs. The reason why this kind of system is a business ethic issue is due to channel members that might have too much control because of their positions and unequal distribution of tasks.