What is the output of this program? abstract class A { int i; abstract void display(); } class B extends A { int j; void display() { System.out.println(j); } } class Abstract_demo { public static void main(String args[]) { B obj = new B(); obj.j=2; obj.display(); } }

• A. 0
• B. 2
• C. Runtime Error
• D. Compilation Error