Interview Questions - PHP Web Development Questions

According to PHP official manual

* Anything from a form
* Anything from $_GET, $_POST, $_REQUEST
* Cookies ($_COOKIES)
* Web services data
* Files

function isbn10_to_13($isbnold){

if (strlen($isbnold) != 10){ // Make sure we have a 10 digit string to start
return 'Invalid ISBN-10, must be 10 digits';
}

When a user first encounters a page in your application that call ssession start(),a sessionis created for the user.PHP generates a random session identifier to identify the user,and then it sends

A. Yes, but not without sending another HTTP request.
B. Yes, because PHP executes before JavaScript.
C. No, because JavaScript is server-side, and PHP is client-side.