Refer to the exhibit. 
Why is the prefix 1.1.1.1/32 not present in the routing table of R1?
A.
There is a duplicate router ID.
B.
There is a subnet mask mismatch on Ethernet0/0.
C.
The router LSA has an invalid checksum.
D.
There is an OSPF network type mismatch that causes the advertising router to be unreachable.