Which of the following is used to destroy a session in PHP?

The function used to destroy a session in PHP is session_destroy(). This function is specifically designed to terminate the current session. When called, it frees all session variables and clears any session data stored on the server, effectively ending the session for the user. After using session_destroy(), the session ID remains, but it cannot be used to access any data, as the data associated with that session is no longer available.

The other options do not perform the function of destroying a session. For instance, session_reset() is used to reset the session variables to their default values but does not terminate the session itself. session_remove() is not a built-in PHP function; therefore, it has no valid implementation for session management. And session_end(), while it sounds plausible, is also not an actual function in PHP for handling sessions. Hence, session_destroy() is the correct and specific method to terminate sessions properly.