A.Router(config)#interface g3/1
Router(config-if)#ip access-group 198 in
Router(config-if)#ip access-group 198 out
Router(config-if)#exit
Router(config)#access-list 198 permit icmp 168.105.129.0 0.0.0.255 any
Router(config)#access-list 198 deny icmp any any
Router(config)#access-list 198 permit ip any any
B.Router(config)#access-list 2000 permit icmp 168.105.129.0 0.0.0.255 any
Router(config)#access-list 2000 deny icmp any any
Router(config)#access-list 2000 permit ip any any
Router(config)#interface g3/1
Router(config-if)#ip access-group 2000 in
Router(config-if)#ip access-group 2000 out
Router(config-if)#exit
C.Router(config)#access-list 198 deny icmp any any
Router(config)#access-list 198 permit icmp 168.105.129.0 0.0.0.255 any
Router(config)#access-list 198 permit ip any any
Router(config)#interface g3/1
Router(config-if)#ip access-group 198 out
Router(config-if)#exit
D.Router(config)#access-list 100 permit icmp 168.105.129.0 0.0.0.255 any
Router(config)#access-list 100 permit ip any any
Router(config)#access-list 100 deny icmp any any
Router(config)#interface g3/1
Router(config-if)#ip access-group 100 in
Router(config-if)#exit