在exam服务目录下有verify.jsp、admin.jsp和error.jsp三个jsp页面。vrify.jsp代码如下：<%@ page contentType="text/html;charset=utf-8" %><% request.setCharacterEncoding("GB2312");String str=request.getParameter("uname");String passwd = request.getParameter("passwd");String role =request.getParameter("role");if(!passwd.equals("123321"))response.sendRedirect("error.jsp");else{if (role!=null && role.equals("admin")) {request.getRequestDispatcher("admin.jsp").forward(request,response);} else {out.print("欢迎您来到本网页！");out.print(str);}}%>error.jsp代码如下：<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><% request.setCharacterEncoding("GB2312");String str=request.getParameter("uname");String passwd = request.getParameter("passwd");if (str !=null )out.println(str+"
");out.print("口令有错！");%>admin.jsp代码如下：<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><%request.setCharacterEncoding("GB2312");String str=request.getParameter("uname");String role = request.getParameter("role");out.println(str+"("+role+") ");out.print("欢迎您来到本网页！");%>在浏览器地址栏内输入请求：http://localhost:8080/exam/verify.jsp?uname=www&passwd=123321&role=stu 则浏览器显示（）

A. www欢迎您来到本网页！
B. www口令有错！
C. 欢迎您来到本网页！stu
D. 欢迎您来到本网页！www