Which of the following statements about a vertical marketing system $($VMS$)$ is true?

Group of answer choices

A VMS is a channel in which there is cooperation among channel members at two or more different levels of the channel.

The three types of vertical marketing systems are independent, conventional, and customized.

Channel conflict is a more serious problem in a vertical marketing system than in a conventional marketing system.

Conventional marketing systems are more efficient than vertical marketing systems.

Members of a VMS operate totally independently of one another outside of buying and selling one another's products.