C# - Binding An Xml Node's Children To DropDownList

I'm trying to bind the contents of a node of XML to a Drop Down List without much success. Initially, the whole XML document is bound to a repeater - this works perfectly, but now I need to display a drop down list based on the children in the "" node, but I get Data at the root level is invalid. Line 1, position 1 error message on the DataBind() method on the dropDownList. The code snippet I'm using is:

IXPathNavigable x = (IXPathNavigable)e.Item.DataItem;
XPathNavigator questionNode = x.CreateNavigator();
string question = questionNode.SelectSingleNode("questionText").ToString();
//string title = xePage.SelectSingleNode("q").InnerText;
Literal questionText = (Literal)e.Item.FindControl("litQuestionText");
questionText.Text = question;
Panel iconDiv = (Panel)e.Item.FindControl("divIcon");
iconDiv.CssClass = string.Format("icon {0}", questionNode.SelectSingleNode("iconType"));
Panel sliderPanel = (Panel)e.Item.FindControl("pnlSlider");
DropDownList answerDropDown = (DropDownList)e.Item.FindControl("ddlAnswer");
TextBox answerText = (TextBox)e.Item.FindControl("txtAnswer");
switch (questionNode.SelectSingleNode("answerType").ToString())
{
case "d":
sliderPanel.Visible = false;
answerText.Visible = false;
answerDropDown.Visible = true;
XmlDataSource answersList = new XmlDataSource();
answersList.Data = questionNode.Select("answers").ToString();
Response.Write(answersList.ToString());
//XPathNodeIterator answers = questionNode.Select("answers");
//answers.AsQueryable();
answersList.ID = questionNode.SelectSingleNode("questionId").ToString();
answerDropDown.DataSource = answersList;
answerDropDown.DataTextField = "@display";....................................