You work as the enterprise exchange administrator at Xxx .The Xxx network consists of a domain named xxx .The Xxx network is running in a Microsoft Exchange Server 2010 environment. Xxx has recently added a distribution group named KingDistribute.How can you allow a user named Dean Austin to manage membership of KingDistribute only but not of the other groups？（）

• A、You must create a new direct role assignment for Dean Austin.
• B、You must view the properties of KingDistribute the add Dean Austin to it.
• C、You must add Dean Austin to KingDistribute’s Managed by list.
• D、You must change the default sharing policy.