A、R1 will send LSAs to R2 and R3 informing them of this change， and then all routers will send periodic updates at an increased rate until the network again converges.

B、Because of the split-horizon rule， router R2 will be prevented from sending erroneous information to R1 about connectivity to the 192.168.1.0 network.

C、When router R2 learns from R1 that the link to the 192.168.1.0 network has been lost， R2 will respond by sending a route back to R1 with an infinite metric to the network.

D、Routers R2 and R3 mark the route as inaccessible and will not accept any further routing updates from R1 until their hold-down timers expire.

E、All routers will reference their topology database to determine if any backup routes to the 192.168.1.0 network are known.