Which system sells goods directly to customers through network of self employed people

Which system sells goods directly to customers through network of self employed people
A: Multilevel marketing
B: Whole sale marketing
C: Vertical marketing
D: None of these

Multilevel marketing is a system where goods are sold directly to customers by independent distributors. These people also recruit others to sell products creating a network. For example companies selling health or beauty products often use MLM. This system reduces cost of retail stores but may face criticism if misused as pyramid schemes.