Scenario
Refer to the topology. Your company has decided to connect the main office with three other remote branch offices using point-to-point serial links.
You are required to troubleshoot and resolve OSPF neighbor adjacency issues between the main office and the routers located in the remote branch offices.
Use appropriate show commands to troubleshoot the issues and answer all four questions.

Instructions
* Enter Cisco IOS commands on the device to verify network operation and answer the multiple-choice questions.
* THIS TASK DOES NOT REQUIRE DEVICE CONFIGURATION.
* Click on the device to gain access to the console of the device. No console or enable passwords are required.
* To access the multiple-choice questions, click on the numbered boxes on the left of the top panel.
* There are four multiple-choice questions with this task. Be sure to answer all four questions before clicking the Next button.

R3 ! interface EthernetO/2 no ip address shutdown ! interface EthernetO/3 no ip address shutdown ! interface Serial1/0 description ***Connected to R4-Branchl office*** ip address 10.10.240.1 255.255.255.252 encapsulation ppp ip ospf 3 area 0 serial restart-delay 0 ! interface Serial1/1 description ***Connected to R5-Branch2 office*** ip address 10.10.240.5 255.255.255.252 encapsulation ppp ip ospf hello-interval 50 ip ospf 3 area 0 !
R4 ! interface EthernetO/2 no ip address shutdown ! interface EthernetO/3 no ip address shutdown ! interface Serial1/0 description ***Connected to R3-Main Branch office*** ip address 10.10.240.2 255.255.255.252 encapsulation ppp ip ospf 4 area 2 serial restart-delay 0 ! interface Serial1/1 no ip address shutdown serial restart-delay 0 interface Seriall/2 no ip address shutdown !
An OSPF neighbor adjacency is not formed between R3 in the main office and R4 the Branch1 office. What is causing the problem?

A.	There is an area ID mismatch.
B.	There is a Layer 2 issue; an encapsulation mismatch on serial links.
C.	There is an OSPF hello and dead interval mismatch.
D.	The R3 router ID is configured on R4.