To increase the availability of an Advanced Replication environment， you can add a new master to a replication group without quiescing the group. This is achieved（）.

• A、Only when the new master site already has existing replication groups. 
• B、By issuing a single command to create, populate, and activate the new master. 
• C、When the master definition site is not the same for all of the master groups. 
• D、Without impacting end users who are executing data manipulation language (DML) commands on the replicated tables.