Provide a different implementation of ChoiceQuestion. Instead of storing the choices in an array list, the addChoice method should add the choice to the question text. For this purpose, an addLine method has been added to the Question class.   ChoiceQuestion.java: /**    A question with multiple choices. */ public class ChoiceQuestion extends Question {    // Add any needed instance variables, but don't store the choices    // The choices should be added to the text of the superclass    /* Your code goes here */        /**       Constructs a choice question with a given text and no choices.       @param questionText the text of this question    */    public ChoiceQuestion(String questionText)    {       /* Your code goes here */    }    /**       Adds an answer choice to this question.       @param choice the choice to add       @param correct true if this is the correct choice, false otherwise    */    public void addChoice(String choice, boolean correct)    {       /* Your code goes here */    } } Question.java: /**    A question with a text and an answer. */ public class Question {    private String text;    private String answer;    /**       Constructs a question with empty text and empty answer.    */    public Question()     {       text = "";       answer = "";    }    /**       Sets the answer for this question.       @param correctResponse the answer    */    public void setAnswer(String correctResponse)    {       answer = correctResponse;    }    /**       Checks a given response for correctness.       @param response the response to check       @return true if the response was correct, false otherwise    */    public boolean checkAnswer(String response)    {       return response.equals(answer);    }    /**       Add a line of text to the question text.    */    public void addLine(String line)    {       text = text + line + "\n";    }    /**       Displays this question.    */    public void display()    {       System.out.print(text);    } } QuestionDemo.java: import java.util.Scanner; public class QuestionDemo {    public static void main(String[] args)    {       Question[] quiz = new Question[2];       quiz[0] = new Question();       quiz[0].addLine("Who was the inventor of Java?");       quiz[0].setAnswer("James Gosling");             ChoiceQuestion question = new ChoiceQuestion(          "In which country was the inventor of Java born?");       question.addChoice("Australia", false);       question.addChoice("Canada", true);       question.addChoice("Denmark", false);       question.addChoice("United States", false);       quiz[1] = question;       Scanner in = new Scanner(System.in);       for (Question q : quiz)       {          q.display();          System.out.println("Your answer: ");          String response = in.nextLine();

ChoiceQuestion.java:

/**
   A question with multiple choices.
*/
public class ChoiceQuestion extends Question
{
   // Add any needed instance variables, but don't store the choices
   // The choices should be added to the text of the superclass
   /* Your code goes here */
   
   /**
      Constructs a choice question with a given text and no choices.
      @param questionText the text of this question
   */
   public ChoiceQuestion(String questionText)
   {
      /* Your code goes here */
   }

   /**
      Adds an answer choice to this question.
      @param choice the choice to add
      @param correct true if this is the correct choice, false otherwise
   */
   public void addChoice(String choice, boolean correct)
   {
      /* Your code goes here */
   }

}

Question.java:

/**
   A question with a text and an answer.
*/
public class Question
{
   private String text;
   private String answer;

   /**
      Constructs a question with empty text and empty answer.
   */
   public Question() 
   {
      text = "";
      answer = "";
   }

   /**
      Sets the answer for this question.
      @param correctResponse the answer
   */
   public void setAnswer(String correctResponse)
   {
      answer = correctResponse;
   }

   /**
      Checks a given response for correctness.
      @param response the response to check
      @return true if the response was correct, false otherwise
   */
   public boolean checkAnswer(String response)
   {
      return response.equals(answer);
   }

   /**
      Add a line of text to the question text.
   */
   public void addLine(String line)
   {
      text = text + line + "\n";
   }

   /**
      Displays this question.
   */
   public void display()
   {
      System.out.print(text);
   }
}

QuestionDemo.java:

import java.util.Scanner;

public class QuestionDemo
{
   public static void main(String[] args)
   {
      Question[] quiz = new Question[2];

      quiz[0] = new Question();
      quiz[0].addLine("Who was the inventor of Java?");
      quiz[0].setAnswer("James Gosling");      

      ChoiceQuestion question = new ChoiceQuestion(
         "In which country was the inventor of Java born?");
      question.addChoice("Australia", false);
      question.addChoice("Canada", true);
      question.addChoice("Denmark", false);
      question.addChoice("United States", false);
      quiz[1] = question;

      Scanner in = new Scanner(System.in);
      for (Question q : quiz)
      {
         q.display();
         System.out.println("Your answer: ");
         String response = in.nextLine();
         System.out.println(q.checkAnswer(response));      
      }
   }
}