如果单选按钮列表中的值null不显示单选按钮mvc4

Question

我在模型中有问题和答案列表。在一些问题中有4个选项，有些问题有2个选项。 我从后端获得选项，我从模型类绑定到剃刀视图。 现在，如果答案值为null意味着单选按钮正在显示，但如果单选按钮选项值为空则我不想要单选按钮。

   @for (int j = 0; j < Model.Count; j++)
                            {
                                i++;
                                <div class="panel-heading online-test" role="tab" id="">
                                    <h5 class="panel-title">
                                        @Html.HiddenFor(m => m[j].ID)
                                        @Html.HiddenFor(m => m[j].SkillId)
                                        @i) @Html.DisplayFor(m => m[j].QuestionText)
                                    </h5>
                                </div>
     foreach (var k in Model[j].Options)
                                {
                                    <div class="panel-collapse">
                                        <div class="panel-body online-test-options">
                                            <div class="input-group">
                                                <div class="col-lg-12" id="radiolist">
                                                    @Html.RadioButtonFor(m => m[j].SelectedAnswer, "A")
                                                    <label for="@k.AnswerId">@k.Option1</label>
                                                </div>
                                                <div class="col-lg-12">
                                                    @Html.RadioButtonFor(m => m[j].SelectedAnswer, "B")
                                                    <label for="@k.AnswerId">@k.Option2</label>
                                                </div>
                                                <div class="col-lg-12">
                                                    @Html.RadioButtonFor(m => m[j].SelectedAnswer, "C")
                                                    <label for="@k.AnswerId">@k.Option3</label>
                                                </div>
                                                <div class="col-lg-12">
                                                    @Html.RadioButtonFor(m => m[j].SelectedAnswer, "D")
                                                    <label for="@k.AnswerId">@k.Option4</label>
                                                </div>
                                            </div>
                                        </div>
                                    </div>
                                }
                         }



public class QuestionsModel
    {
        public decimal ID { set; get; }
        public decimal SkillId { get; set; }
        public string QuestionText { set; get; }
        public List<Answer> Options { set; get; }
        public string SelectedAnswer { set; get; }
        public QuestionsModel()
        {
            Options = new List<Answer>();
        }
    }
    public class Answer
    {
        public int AnswerId { get; set; }
        public string Option1 { set; get; }
        public string Option2 { set; get; }
        public string Option3 { set; get; }
        public string Option4 { set; get; }
    }
    public class Evaluation
    {
        public List<QuestionsModel> Questions { set; get; }
        public Evaluation()
        {
            Questions = new List<QuestionsModel>();
        }
    }

请帮忙解决.. 在此先感谢。