Given the following program:

public interface Flyer $\{$

public void fly$()$;

$\}$

public class Plane implements Flyer $\{$

@Override

public void fly$()\{$

System.out.println$("$Cruising at $35,000$ ft$...")$;

$\}$

$\}$

public class Seagull implements Flyer $\{$

@Override

public void fly$()\{$

System.out.println$("$Soaring with the wind..."$)$;

$\}$

$\}$

public class Launcher $\{$

public void launch$($Flyer flyer$)\{$

System.out.println$("$Go fly, oh flyer!"$)$;

flyer.fly$()$;

$\}$

public void refuel$($Plane plane$)\{$

System.out.println$("$Refueling the plane..."$)$;

$\}$

$\}$

public class FlyerApp $\{$

public static void main$($String$[]$ args$)\{$

Launcher launcher $=$ new Launcher$()$;

Flyer plane $=$ new Plane$()$;

Flyer seagull $=$ new Seagull$()$;

$//$ launcher.launch$($plane$)$; $//$ A

$//$ launcher.launch$($seagull$)$; $//$ B

$//$ launcher.refuel$($plane$)$; $//$ C

$\}$

$\}$