Final answer:
Repadmin is the correct tool for monitoring Active Directory replication between domain controllers in different Active Directory sites.
Step-by-step explanation:
The correct tool for monitoring Active Directory replication between domain controllers distributed in other Active Directory sites is Repadmin. This command-line tool assists administrators in diagnosing replication issues. Repadmin is not the only tool available, but it is widely used due to its robust set of features for replication management and reporting. To monitor replication, one might use commands like repadmin /replsummary to get an overview of the replication status, or repadmin /showrepl to see the replication details for a particular domain controller. These commands help to provide critical information on the health and status of the replication processes between different sites.