Which line in the following OSPF configuration will not be required for MD5 authentication to work?
interface GigabitEthernet0/1
ip address 192.168.10.1 255.255.255.0
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 CCNA
!
router ospf 65000
router-id 192.168.10.1
area 20 authentication message-digest
network 10.1.1.0 0.0.0.255 area 10
network 192.168.10.0 0.0.0.255 area 0
!

A.
ip ospf authentication message-digest

B.
network 192.168.10.0 0.0.0.255 area 0

C.
area 20 authentication message-digest

D.
ip ospf message-digest-key 1 md5 CCNA

Explanation:
BD
This is an exact question from the Cisco Official Certification Guide 210-260.
Source: Cisco Official Certification Guide, Table 13-1 “Do I Know This Already?” Section-to-Question Mapping,
p.342