how to route the traffic arriving at R1 for 10.1.3.1?

Based on the network provided in the exhibit, how to route the traffic arriving at R1 for 10.1.3.1?

A.
through R3, since the path through R3 is through the backbone

B.
through R2, because that is the only path available; no neighbor adjacency will be built between
R1 and R2

C.
through R1, since the path through R1 has the lowest hop count

D.
through R1, since the path through R1 has the lowest total metric (10+10=20, versus
10+10+10=30 through R3)

Explanation:
R1 & R2 will not form a OSPF neighbor relationship because they are in two different areas. R2

s0/0(10.1.1.2/24) is in Area 2 and R1 s0/0 is in area 1 (10.1.1.1/24). Therefore traffic will pass from
R1 to R3 to R2 when going to the 10.1.3.0/24 network.