下列代码中的内部类名是______。  
import java.awt.event.*;
import javax.swing.*;
class Talkingclock{
       public void start(int interval, final boolean beep){
              ActionListener listener=new  ActionListener(){
                     public void actionPerformed (ActionEvent event) {
                            ......
                     }
              }
              Timer t=new Timer(interval, listener);
              t. start();
       }
}  
A、Timer
B、ActionListener
C、 listener
D、匿名