The Oracle Shared Server architecture reduces memory usage by reducing the number of server processes required. To process a request for a server process， the following tasks are performed： 1.A shared server picks up the request from the request queue and processes the request. 2.The dispatcher retrieves the response from the response queue. 3.A user sends a request to its dispatcher. 4.The dispatcher returns the response to the user. 5.The shared sever places the response on the calling dispatcher’s response queue. 6.The dispatcher places the request into the request queue in the SGA. Put the above task in the order in which they are performed.（）

A. 3，1，6，2，5，4
B. 3，6，1，5，2，4
C. 3，1，2，3，4，5
D. 6，1，3，5，2，4
E. 6，3，1，2，4，5
F. 6，3，1，2，5，4