When is a destructor called in a PHP class?

In PHP, a destructor is called when an object is no longer referenced or explicitly destroyed. The correct option is "When an object is no longer referenced or explicitly destroyed." The destructor is automatically triggered by PHP's garbage collection mechanism when there are no more references to the object, or when the unset() function is used to explicitly destroy the object. This allows the destructor to perform any necessary cleanup tasks before the object is freed from memory. For more details, refer to the PHP documentation on destructors: https://www.php.net/manual/en/language.oop5.decon.php#language.oop5.decon.destruct