现有： 
class  Wrench2  {     
int size； 
public static void main（String  []  args）  {     
Wrench2 w=new Wrench2（）；     
w.size=II； 
Wrench2 w2=go（w， w.size）；    
System. out .print （w2. size）；     
} 
static Wrench2 go（Wrench2 wr. int s）  {     
S=12； 
return wr；    
}    
}
结果为（）    

A. 11
B. 12
C.编译失败
D.运行时异常被抛出