In a CRS cluster with Standby Servers, which of the following statements are true? （）

• A、The Standby Server can be installed across the WAN from the active server. 
• B、MS SQL 2000 must be installed for the datastores. 
• C、MS SQL 2000 or MSDE can be installed for the datastores. 
• D、On the Standby Server, you must install the same components that are installed on its corresponding active server. 
• E、The Standby Server can be installed on one of the CallManager servers.
• F、The active server can be installed on one of the CallManager servers.