下列代码正确的是哪项？（） 

A、 public class Session implements Runnable， Clonable{   public void run （）；public Object clone （） ； }

B、 public class Session extends Runnable， Cloneable {  public void run（） {/*dosomething*/}       public Object clone（） {/*make a copy*/} }

C、 public abstract class Session implements Runnable， Clonable {       public void run（） {/*do something*/}       public Object clone（） {/*make a copy*/}        }

D、 public class Session implements Runnable， implements Clonable {       public void run（） {/*do something*/}       public Object clone（） {/*make a copy*/}       }