In the following code, which classes can be instantiated? abstract class Graphics { abstract
function draw($im, $col); } abstract class Point1 extends Graphics { public $x, $y; function
__construct($x, $y) { $this->x = $x; $this->y = $y; } function draw($im, $col) {
ImageSetPixel($im, $this->x, $this->y, $col); } } class Point2 extends Point1 { } abstract
class Point3 extends Point2 { }

A.
Point3
B.
Point2
C.
Point1
D.
Graphics
E.
None, the code is invalid