R1, an ABR between backbone area 0 and area 1, has intra-area routes in area 0 for
10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24. These routes have metrics of 21, 22, and 23,
respectively. An engineer then adds the area 0 range 10.1.0.0 255.255.0.0 command under
the OSPF process of R1. Which of the following is true? (Choose two.)

A.
R1 loses and then re-establishes neighborships with all neighbors.

B.
R1 no longer advertises 10.1.1.0/24 to neighbors into area 1.

C.
R1 advertises a 10.1.0.0/16 route into area 1 with a metric of 23 (largest metric).

D.
R1 advertises a 10.1.0.0/16 route into area 1 with metric of 21 (lowest metric).

Explanation:
The area range command does not cause a failure in neighborships. Because at least one
intra-area subordinate subnet of 10.1.0.0/16 exists in R1, R1 both creates a summary route
for 10.1.0.0/16 and stops advertising LSAs for the (three) subordinate subnets. By default,
the metric of the summary is the metric of the lowest-metric component subnet.