You cannot delete a cookie from a client computer.
Correct:
You cannot delete a cookie from a client computer.
Explanation: Answer option B is correct.
You cannot remove a cookie from a client computer. You have to set the cookie time in the past to make it expire. For example, in order to make a cookie expire, you can set the expiration time to one hour ago:
<?php
setcookie("user", "", time()-3600);
?>
Setting up a cookie value
The setcookie() function is used to set a cookie to be sent along with the rest of the HTTP headers. For example, a user will use the following script to create a cookie named "user", assign the value "Jason", and specify that the cookie should expire after one hour:
<?php
setcookie("user", "Jason", time()+3600);
?>
Since cookies must be sent before any output from the script, the setcookie() function must appear before the tag.
Answer option D is incorrect. The session.gc_maxlifetime INI setting sets the time duration since the last access. After that, the session handler considers a session data file as a garbage file and marks it for deletion by the garbage handler.
Answer options C and A are incorrect. These are not valid PHP functions.