Study the classes below:

class A$\{$

protected $name, $id;

private static $number $=1$;

public function $\_\_$construct$($$na$)\{$

$this$->$name $=$ $na;

$this$->$id $=$ self::$number;

self::$number$++$;

$\}$

public function setName$($$na$)\{$

$this$->$name $=$ $na;

$\}$

public function getName$()\{$

return $this$->$name;

$\}$

public function getID$()\{$

return $this$->$id;

$\}$

public function toString$()\{$

return $"$$this$->$name,$this$->$id$"$;

$\}$

$\}$

class B extends A$\{$

protected $type;

public function $\_\_$construct$($$na$,$ $ty$)\{$

$this$->$type $=$ $ty;

parent::$\_\_$construct$($$na$)$;

$\}$

public function setType$($$ty$)\{$

$this$->$type $=$ $ty;

$\}$

public function getType$()\{$

return $type;

$\}$

public function toString$()\{$

return parent::toString$().",".$$this$->$type;

$\}$

$\}$

Which one of the following options is correct for the code above?