How can I disable "Delete the account and its content"? On the Cancel account page, is it possible to disable the option "Delete the account and its content"?

Some roles have the permission to cancel user accounts, but they should not have the option to delete the user's content.
You can implement hook_form_alter() in a custom module or theme to either remove the radio button entirely, or disable it which grays it out. You'd need to add additional logic to check the role of the user and disable it appropriately. I've shown both examples in the code example below, just uncomment the one you want to use.

function mymodule_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  if ($form['#id'] == 'user-multiple-cancel-confirm') {
    // Set '#access' to FALSE to remove the radio button.
    // $form['user_cancel_method']['user_cancel_delete']['#access'] = FALSE;

    // Set '#disabled' to TRUE to disable the radio button.
    // $form['user_cancel_method']['user_cancel_delete']['#disabled'] = TRUE;
  }
}