DataClassInfo info = DataClassInfoProvider.GetDataClass("<class name>");
if (info != null)
{
    CMS.FormEngine.FormInfo fi = new CMS.FormEngine.FormInfo(info.ClassFormDefinition);
    CMS.FormEngine.FormFieldInfo ffi = fi.GetFormField("<field name>");
    string a = ValidationHelper.GetString(ffi.Settings["options"], "");

    System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
    xmlDoc.LoadXml("<xml>" + Convert.ToString(ffi.Settings["options"]) + "</xml>");

    System.Xml.XmlNode xmlNode = xmlDoc.FirstChild;

    if (xmlNode.HasChildNodes)
    {
       foreach (System.Xml.XmlNode itemNode in xmlNode.ChildNodes)
       {
          string text = CMSContext.CurrentResolver.ResolveMacros(XmlHelper.GetAttributeValue(itemNode, "text"));
          string value = CMSContext.CurrentResolver.ResolveMacros(XmlHelper.GetAttributeValue(itemNode, "value"));
       }
    }
}