Which three statements are true about the naming methods and their features supported by Oracle database used to resolve connection information?

A. A client can connect to an Oracle database instance even if no client side network admin has been configured.

B. Directory Naming requires setting the TNS ADMIN environment variable on the 

C. Directory Naming can be used if Connect-Time Failover is required.

E. Local Naming requires setting the TNS_ADMIN environment variable on the cdient side.

F. Local naming can be used if Connect-Time Failover is required.

求解