Which of the following PHP function is commonly used when handling authentication via PHP? i) $_SERVER[ PHP_AUTH_USER ]. ii) $_SERVER[ PHP_AUTH_USERS ]. iii) $_SERVER[ PHP_AUTH_PU ]. iv) $_SERVER[ PHP_AUTH_PW ].

• A. I) and iv)
• B. Ii) and iv)
• C. Ii) and iii)
• D. I) and iii)