现有： 
class Wrench f 
public static void main（String  []  args）  { 
Wrench w=new Wrench（）；    Wrench w2=new Wrench（）；    
w2=go （w， w2）；     
System.out.print （w2==w）；     
} 
static Wrench go （Wrench wrl，  Wrench wr2）  {    
Wrench wr3=wrl； wrl=wr2； wr2=wr3；    
return wr3；     
}      
结果是什么？（）     

A. false
B. true
C.编译失败
D.运行的时候有异常抛出