现有: <br /> class Top  {    <br /> static int X=l; <br /> public Top()  {  x*=3; }    <br /> } <br /> class Middle extends Top  {     <br /> public  Middle()    {x+=l;  } <br /> public static void main(String  []  args)  {    <br /> Middle m=new Middle();   <br /> System.out.println (x);   <br /> }    <br /> } <br /> 结果是什么?()    <p> 现有: <br /> class Top  {    <br /> static int X=l; <br /> public Top()  {  x*=3; }    <br /> } <br /> class Middle extends Top  {     <br /> public
A、A. 2
B、B. 3
C、C. 4
D、D.编译失败