What is the path for form elements which are ajax-enabled I am working on the quiz module.
I have to modify the form node/add/multichoice by hiding some of the form elements in it.
With the help of krumo function of devel module, I am able to find the correct form elements and set ['#access'] to FALSE in order to hide them.
All this is done in a custom module using the hook_form_alter().      

But the problem is that I have to hide advanced fieldset under alternatives.
The path for form element for advanced fieldset is thus like below :
$form['alternatives'][0]['advanced']
$form['alternatives'][1]['advanced']
But there is an option of add more alternatives.
What is the path for form elements which are ajax enabled.
foreach (element_children($form['alternatives']) as $delta) {
  $form['alternatives'][$delta]['advanced']['#access'] = FALSE;
}


Something like this.