This question is asking about subnet 192.168.10.0 not been able to access the remote network. The output shows it is ospf network configuration. For it to access remote network it is going to need the mac address of the router. This question does not have anything to do with submet 192.168.12.0. I think the ospf process will work in as much it it not using the 192.168.12.0 network according to the question.
The mask on the link is wrong . A /31 will not give two valid host ip to assign to the router interfaces. Changing the mask to a /30 will meet the requirement.
The mask on the link is wrong . A /31 will not give two valid host ip to assign to the router interfaces. Changing the mask to a /30 will meet the requirement.