问题：

[单选]

Following ticket consists of a problem description and existing configuration on the device.

Figure 1
Cisco 642-832： Practice Exam

Figure 2
Trouble Ticket Statement：
Client 1 is able to ping 10.1.1.2 but not 10.1.1.1. Initial troubleshooting shows that R1 does not have anyOSPF neighbors or any OSPF routes
Configuration on R1：
router ospf 1
CertKiller.com
log-adjacency-changes
network 10.1.1.0 0.0.0.3 area 12
default-information originate always!
interfaceSerial0/0/0/0.12 point-to-point
ip address 10.1.1.1 255.255.255.252
ip nat inside
ip ospf message-digest-key 1 md5 TSHOOT
Configuration on R2：
router ospf 1
log-adjacency-changes
network 10.1.1.0 0.0.0.3 area 12!
Cisco 642-832： Practice Exam
interfaceSerial0/0/0/0.12 point-to-point
ip address 10.1.1.2 255.255.255.252
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 TSHOOT
What is the solution of the fault condition？（）

A . ipospf authentication message-digestcommand has to be added on S0/0/0/0.12
B . ipospf authentication message-digestcommand has to be added under the OSPF routing process
C . A static route to 10.1.1.4 must be added on R1
D . ipnat outside must be added on S0/0/0/0.12