单项选择题

有如下程序
public class Test
int a,b;
Test()
a=100;
b=200;
Test(int x,int y)
a = x;
b = y;
public static void main(String args[])
Test Obj1=new Test(12,45);
System.out.println("a = "Obj1.a+" b= "+Obj1.B) ;
Test Obj1=new Test();
System.out.println("a = "Obj1.a+" b= "+Obj1.B) ;
程序的运行结果为( )。