Which of the Following Is a Difference Between Vertical Restraints

Which of the following is a difference between vertical restraints and horizontal restraints?

A) Vertical restraints,in general,are based on tacit understanding while horizontal restraints,in general,are based on mutual observation.
B) Vertical restraints eliminate competition,while horizontal restraints promote competition.
C) Vertical restraints are those arising from an agreement among competitors themselves,while horizontal restraints ordinarily are those imposed by suppliers on their buyers.
D) Vertical restraints,in general,are resolved under the rule of reason while horizontal restraints,in general,are per se unlawful.