Dropdown list value from Odata

Hi,

I want to get dropdown list value from Odata.  Please find script below and kindly help me to find solution. what I can give to get value of dropdown list in retrieved.results[0].new_Department.  I mean option set value 1,2,3 etc.

var clientid = Xrm.Page.getAttribute("new_initiated").getValue()[0].id;
var context = Xrm.Page.context;
serverUrl = context.getServerUrl(); 
var ODataPath = serverUrl + "/XRMServices/2011/OrganizationData.svc";
var retrieveResult = new XMLHttpRequest();
retrieveResult.open("GET", ODataPath + "/SystemUserSet?$select=new_Department&$filter=SystemUserId eq guid'" + clientid + "'", false);
retrieveResult.setRequestHeader("Accept", "application/json");
retrieveResult.setRequestHeader("Content-Type", "application/json; charset=utf-8");
retrieveResult.send();
if (retrieveResult.readyState == 4 )
   {
      if (retrieveResult.status == 200)
            {
             var retrieved = JSON.parse(retrieveResult.responseText).d;
             alert(retrieved.results[0].new_Department);
             Xrm.Page.getAttribute("new_department").setValue(retrieved.results[0].new_Department);
     }
    }