单项选择题

下面程序段的输出结果为
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 Obj2=new Test();
System.out.println("="+Obj2.a+" b="+Obj2.B) ;

A.a=100 b=200
a=12 b=45
B.a=12 b=45
a=100 b=200
C.a=12 b=200
a=100 b=45
D.a=100 b=45
a=12 b=200