Java Head First exercise

Question

I've got a problem with exercise in Java Head First. Basically I don't understand why output changes based on frighten's methode argument. I don't get what impact on output have values returned by classes Dragon, Vampire and Monster.

public class MonsterTestDrive {
    public static void main(String [] args) {
        Monster [] ma = new Monster[3];
        ma[0] = new Vampire();
        ma[1] = new Dragon();
        ma[2] = new Monster();
        for(int x = 0; x < 3; x++) {
            ma[x].frighten(x);
        }
    }
}

class Monster {

// A

} 

class Vampire extends Monster {

// B

}

class Dragon extends Monster {
    boolean frighten(int degree) {
        System.out.println(“breath fire”);
        return true;
    }
}

Which of the A-B pairs of methods listed on the right, if inserted into the classes on the left, would compile and produce the output shown?

(The A method inserted into class Monster, the B method inserted into class Vampire.)

 //1
boolean frighten(int d) {     
    System.out.println(“arrrgh”); //A
    return true;
}
boolean frighten(int x) {
    System.out.println(“a bite?”);//B
    return false;
}

//2
boolean frighten(int x) {
    System.out.println(“arrrgh”);//A
    return true;
}
int frighten(int f) {
    System.out.println(“a bite?”);//B
    return 1;
}

//3
boolean frighten(int x) {
    System.out.println(“arrrgh”); //A
    return false;
}
boolean scare(int x) {
    System.out.println(“a bite?”);//B
    return true;
}

//4
boolean frighten(int z) {
    System.out.println(“arrrgh”);//A
    return true;
}
boolean frighten(byte b) {
    System.out.println(“a bite?”);//B
    return true;
}

Exercise img