If you get a DataTable with the data, you can create a DataView off of this and then bind the drop down list to that. Your code would look something like...
DataView dvOptions = new DataView(DataTableWithOptions);
dvOptions.Sort = "Description";
ddlOptions.DataSource = dvOptions;
ddlOptions.DataTextField = "Description";
ddlOptions.DataValueField = "Id";
Your text field and value field options are mapped to the appropriate columnns in the data table you are receiving.