20(Must%20download% Cb Best C++ Formatt... G calculator - optimize.dvi 3/7 110% Question 1. (20 marks) (a) [13 marks] Complete the given program according to the explanation below: Consider that: When person X meets Y the first time, X says "Hi [Mr Y's namel/[Ms Y's namel, this is X's name" As a further requirement: When X and Y meet again, each one's saying is "Nice to meet you again!" You are given main() and two classes Male and Female. Please complete the class Person so as to make the program work. The program should give the outputs as shown in the comments within the square brackets [] inside main(). a.sayHiTo (b); //Output [Hi Mr Lee, this is Poon] a. sayHiTo (c); //Output [Hi Ms Johnson, this is Poon] c.sayHiTo (b); //Output [Hi Mr Lee, this is Johnson] c.sayHiTo(d); //Output [Hi Ms Smith, this is Johnson] a. sayHiTo (b); //Output [Nice to meet you again!] b.sayHiTo(a); //Output [Nice to meet you again!] c.sayHiTo(a); //Output [Nice to meet you again!] +1 Note: Do not use the instanceof operator. Otherwise you will get 0 mark for this question. Given code: public class Main ( public static void main (String[] args) ( Person a new Male ("Poon"); Person b= new Male ("Lee"); Person c= new Female("Johnson"); Person d new Female ("Smith"); a.sayHiTo(d); //Output [Hi Ms Smith, this is Poon] d.sayHiTo(a); //Output [Nice to meet you again!] d.sayHiTo (b); //Output [Hi Mr Lee, this is Smith] d. sayHiTo (b); //Output [Nice to meet you again!] A SANDONG public class Male extends Person ( public Male(String n) { super(n); } public String title() { return "Mr"; } public class Female extends Person ( public Female (String n) { super(n); } public String title() { return "Ms"; ) (b) (4 marks) Using any code in part (a), explain the terms (i) Up-casting and (ii) Dynamic Binding. If any of them is not observed in the code, please write "not appear in the code". (c) [3 marks] State 3 reasons for using an abstract class instead of an interface in Java programming.