Match each queuing system term to its correct description

A common line is formed. The customer at the head of the line proceeds to the initial service provider who provides part of the service, and the customer is then passed$-$off to the next service provider in sequence, and so on$,$ until the full service is completed.

A common line is formed. The customer at the head of the line proceeds to the first available service provider $($from a group of service providers$),$ who completes the required service for the customer.

A common line is formed, and the customer at the head of the line proceeds to the first available service provider $($from a group of service providers$),$ who provides part of the service, and the customer is then passed$-$off to the next service provider in sequence, and so on$,$ until the full service is completed.

A common line is formed. The customer at the head of the line proceeds to the single service provider who completes the required service for the customer.