What is the purpose of this command? ip route 0.0.0.0 0.0.0.0 serial0/0（）

• A、It configures a router to send all packets out interface serial 0/0.
• B、It configures a router to block routing updates from being sent out interface serial 0/0.
• C、It configures a router as a firewall, blocking all unauthorized packets from exiting serial 0/0.
• D、It configures a router to send all packets for unknown destination networks out interface serial 0/0.
• E、It configures a router to drop all packets for which the destination network is unknown.