Which statement is true regarding Oracle Shared Server architecture？（）

• A、A dispatcher can support multiple client connects concurrently while a shared server process can be dedicated to only one dispatcher. 
• B、Under the Oracle Shared Server architecture, client-user processes connect to shared user processes.
• C、Each dispatcher has its own request queue, which is monitored every three seconds by the dispatcher. 
• D、Oracle Shared Server required Oracle Net Service even if the client and shared server processes reside on the same machine.