Click the Exhibit button and examine the diagram， which illustrates the components performing tasks within an Oracle Shared Sever environment. Which task is being performed by component 4？（）

A. The PMON process registers the request in the response queue.
B. A shared sever places the process request in the response queue.
C. A request within the request queue is processed by an idle shared server process.
D. A dispatcher assigns a request from the request queue to and idle shared server process.