At the end of the execution of the following script, which values will be stored in the $a->my_value array? (Choose 3)

class my_class
{
var $my_value = array();
function my_class ($value)
{
$this->my_value[] = $value;
}
function set_value ($value)
{
$this->$my_value = $value;
}
}
$a = new my_class ('a');
$a->my_value[] = 'b';
$a->set_value ('c');
$a->my_class('d');

• c
• b
• a
• d
• e

Answers:
b,a and d

The set_value method of my_class will not work correctly because it uses the expression $this->$my_value, which is a “variable variable” that, under the circumstances will never correspond to any real property of the class.