Which three of the following are valid CRS deployment scenarios? （）

• A、High Availability CRS Engines running on hardware from different server classes 
• B、High Availability CRS Engines running on similar hardware from the same server class but from different vendors 
• C、High Availability CRS Engines and database and a simplex Recording Server 
• D、High Availability CRS Engines and four simplex VoIP Monitoring Servers 
• E、CCM co-resident deployment on an MCS 7815