Redistribution between multiple OSPF domains caused a routing loop. Which action prevents the loop?

The correct action is to set a tag during redistribution and then filter based on that tag. When redistributing routes from one OSPF domain into another, you can assign a tag to those routes using a route-map with the set tag command. In the other OSPF domain, you can then create a route-map that denies routes with that specific tag from being redistributed back, effectively preventing a routing loop. The incorrect options propose setting a tag using the network command, which is used for advertising interfaces into OSPF, not for tagging redistributed routes. They also suggest denying tags when exiting a domain, which might not prevent the loop if the route has already been learned and re-advertised within the second domain. The key is to prevent the re-entry of the redistributed route back into its original domain or an adjacent domain that would forward it back.