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.