One of your customer has six sites， three of which process a large amount of traffic among them.He plans to grow the number of sites in the future. Which is the most appropriate design topology？（）

A. IGRP
B. RIP
C. RIPv2
D. OSPF

A. passively listens to network traffic
B. is an active device in the traffic path
C. has a permissive interface that is used to monitor networks
D. traffic arrives on one IPS interface and exits on another

A. route list
B. route group
C. gateway list
D. route pattern