Which of the following answers can be verified as true based on the following command output from Router R1?

Which of the following answers can be verified as true based on the following command
output from Router R1?
R1#show ip ospf virtual-links
Virtual Link OSPF_VL0 to router 4.4.4.4 is up
Run as demand circuit
DoNotAge LSA alloweD.
Transit area 1, via interface FastEthernet0/1, Cost of using 3

A.
R1 is configured with an area 0 virtual-link 4.4.4.4 cost 3 command.

B.
The ping 4.4.4.4 command on R1 must currently be successful.

C.
R1’s Fa0/0 OSPF cost is 3.

D.
4.4.4.4 is known to R1 based on a Type 1 LSA in area 1.

Explanation:
The answer with area 0 virtual-link 4.4.4.4 cost 3 is incorrect because the show
command output lists a transit area of 1, but the answer’s area parameter refers to
area 0 as the transit areA. (There is also no cost parameter on the area virtual-link
command.) The RID of the router on the other end of the virtual link, 4.4.4.4 per the
show command output, does not have to be pingable for the virtual link to work. The
cost of the virtual link is 3, but that cost is calculated as the cost to reach the other
router through the transit area, so the command output listed with the question can not be
used to predict Fa0/0’s OSPF interface cost alonE. However, because the output

lists area 1 as the transit area, and because the neighbor RID is listed as 4.4.4.4,
R1 will use the area 1 LSDB entries to calculate the cost to reach 4.4.4, a process that
will include the area 1 Type 1 LSA for RID 4.4.4.4.