Is there a typo in option 1? Is it supposed to call 'forward' rather than 'dispatch'?
req.getRequestDispatcher("errorpage.jsp").dispatch(req, res, HttpServletResponse.SC_FORBIDDEN);
The note in the explanation says:
1. Dispatching a request to another JSP will not send a HTTP status message to the client. Also, the forward method of RequestDispatcher does not take 3rd argument.
Apart from the fact that RequestDispatcher doesn't have a dispatch(), the above explanation doesn't make sense unless it calls 'forward'.