单项选择题

class Wrench { 
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 wr1, Wrench wr2) { 
Wrench wr3 = wr1; wr1 = wr2; wr2 = wr3; 
return wr3;
} 
} 
结果是什么?() 

A.true
B.false
C.编译失败
D.输出不可预期