What will be the output of the following Java program?
class A
{
int i;
public void display()
{
System.out.println(i);
}
}
class B extends A
{
int j;
public void display()
{
System.out.println(j);
}
}
class Dynamic_dispatch
{
public static void main(String args[])
{
B obj2 = new B();
obj2.i = 1;
obj2.j = 2;
A r;
r = obj2;
r.display();
}
}
a) 1
b) 2
c) 3
d) 4

Answer: b
Explanation: r is reference of type A, the program assigns a reference of object obj2 to r and uses that reference to call function display() of class B.