Refer to the exhibit. In this network，R1 has been configured to advertise a summary route， 192.168.0.0/22，to R2. R2 has been configured to advertise a summary route，192.168.0.0/21， to R1. Both routers have been configured to remove the discard route （the route to null created when a summary route is configured） by setting the administrative distance of the discard route to 255. What will happen if R1 receives a packet destined to 192.168.3.1？ （）
- AThe packet will loop between R1 and R2
- BIt is not possible to set the administrative distance on a summary to 255
- CThe packet will be forwarded to R2，where it will be routed to null0
- DThe packet will be dropped by R1，since there is no route to 192.168.3.1