added 'an' and 'the' to ngOptions sentence

src/ng/directive/select.js

@@ -29,7 +29,7 @@ var ngOptionsMinErr = minErr('ngOptions');
  * option. See example below for demonstration.
  *
  * <div class="alert alert-warning">
- * **Note:** `ngOptions` provides iterator facility for `<option>` element which should be used instead
+ * **Note:** `ngOptions` provides an iterator facility for the `<option>` element which should be used instead
  * of {@link ng.directive:ngRepeat ngRepeat} when you want the
  * `select` model to be bound to a non-string value. This is because an option element can only
  * be bound to string values at present.