When congestion occurs, queuing strategies can be varied. If you need to service the first-arriving packets first, you can use the ( ) queuing strategy; if you want to ensure that the most urgent and critical business is served first, you can use the ( ) queuing strategy; if you need to balance the delay and delay jitter of each stream, you can choose ( ) queuing strategy; if you want to provide professional bandwidth for specific services, you can choose ( ) queuing strategy.
A . FIFO 、 PQ 、 WFQ 、 CQ
B . FIFO 、 CQ 、 PQ 、 WFQ
C . WFQ 、 PQ 、 CQ 、 FIFIO
D . PQ 、 FIFO 、 WFQ 、 CQ
Answer: A