现有：    
class Pencil  { 
public void write （String content）{     System.out.println （"Write"+content）；     }     } 
class RubberPencil extends Pencil{     public void erase （String content）{     System.out.println （"Erase"+content）；     }     } 
执行下列代码的结果是哪项？（）     
Pencil pen=new RubberPencil（）；     
pen.write （"Hello"）；     
pen.erase （"Hello"）；    

A. Write Hello        Erase Hello
B. Erase Hello        Write Hello
C.编译错误
D.运行时抛出异常