What is the new Oracle Shared Server?（）

• A、An improved version of multithreaded server configuration. 
• B、A connection pooling configuration where several clients are connected to the same server process. 
• C、Two more database servers, which share data by means of database links; the client software is unaware to which server it is connected. 
• D、A configuration of Real Application Cluster where the client connection is routed to the least busy instance.