You have an organization that contains Exchange Server 2007 and Exchange Server 2010 Hub Transport servers.You create a moderated distribution group named Group1. You assign a user named User1 as the group’s mderator.User1 reports that some e-mails are delivered to members of Group1 without his approval.You need to ensure that all e-mails delivered to Group1 are approved by user1. What should you do？（）

A. Modify the expansion server for the group.
B. Restart the MSExchangeTransport Service.
C. Force a replication between all domain controllers.
D. Recreate the group as a dynamic distribution group.