![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
给定一个Servlet的代码片段如下所示: public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{ String str = "world"; HttpSession session = request.getSession(); session.setAttribute("str", str); ___________________ } 要取出session中的值,下划线处的代码可以是() (5.0分) A. String s = session.getParameter("str"); B. String s = (String)session.getAttribute("str"); C. Object o = session.getAttribute("str"); D. Object o = (Object)session.getParameter("str");