Index: includes/form.inc
===================================================================
--- includes/form.inc	(revision 1)
+++ includes/form.inc	(working copy)
@@ -2005,7 +2005,10 @@
       else {
         $selected = '';
       }
-      $options .= '<option value="' . check_plain($key) . '"' . $selected . '>' . check_plain($choice) . '</option>';
+      if (is_array($element['#options_attributes'])) {
+        $options_attributes = ' ' .drupal_attributes($element['#options_attributes'][$key]);
+      }
+      $options .= '<option value="'. check_plain($key) .'"'. $selected .$options_attributes .'>'. check_plain($choice).'</option>';
     }
   }
   return $options;