发送列表以查看，填写并在 asp.net MVC中获取

我有一个测验表格，它显示一些带有答案的问题（单选按钮），用户必须回答问题并发送，我做了这样的课程：

  public class Question 
{
    public int Qid { get; set; }
    public string Questionstext { get; set; }
    public int selected { get; set; }
    public List<Qitem> lst { get; set; }
}
public class Qitem
{
    public int id { get; set; }
    public string txt { get; set; }
}

然后我发送一个问题列表到视图中：

 List<Question> llst = new List<Question>
        {
            new Question
            {
                Qid = 1,
                Questionstext = "is it true?",
                lst = new List<Qitem>
                {
                    new Qitem
                    {
                        txt = "yes",
                        id = 1
                    },
                    new Qitem
                    {
                        id = 2,
                        txt = "no"
                    }
                }
            },
            new Question
            {
                Qid = 1,
                Questionstext = "is it true 2?",
                lst = new List<Qitem>
                {
                    new Qitem
                    {
                        txt = "yes2",
                        id = 3
                    },
                    new Qitem
                    {
                        id = 4,
                        txt = "yes3"
                    }
                }
            }
        };
        return View(llst);

我如何显示它然后提交答案，答案必须放在问题的"选定"属性中。我的问题是关于视图和特别是单选按钮。

@model List<Question>
@using (Html.BeginForm())
{
    for (int i = 0; i < Model.Count; i++)
    {
        @Html.HiddenFor(m => m[i].Qid)
        <h2>@Model[i].Questionstext</h2>
        foreach (var answer in Model[i].lst)
        {
            <label>
                @Html.RadioButtonFor(m => m[i].selected, answer.id, new { id = "" })
                <span>@answer.txt </span>
            </label>
        } 
    }
    <input type="submit" value="Save" />
}

public ActionResult Index(List<Question> model)