Consider the system composed of four processes linked by a conveyer belt. There is no storage between these processes pictured below and market demand ef $40$ units per hour drives the conveyor belt. Assume that no defective units are made. Which statement is best?Process $1$Inventory$4$ unitsProcess $2$Inventory$5$ unitsProcess $3$Inventory$6$ unitsProcess $4$Inventory $-7$ unitsSelect one: A$.$ The flow rate through the entire process is $160$ units per hour. B$.$ The avorago time a unit spends in Process $1$ is $2$ and a half minutes. C$.$ The average time a unit spends in Process $2$ is $5$ minutes. D$.$ The flow time for a unit trough the entire process is $33$ minutes.