How to create custom template suggestion, when there is no hook suggestion?
You can do it this way 


implement hook_theme_registry_alter like the following:




    /**
     * Implements hook_theme_registry_alter().
     */
    function YourCostumModuleName_theme_registry_alter(&$theme_registry) {
      // Defined path to the current module.
      $module_path = drupal_get_path('module', 'YourCostumModuleName') . "/templates";
      // Find all .tpl.php files in this module's folder recursively.
      $template_file_objects = drupal_find_theme_templates($theme_registry, '.tpl.php', $module_path);
      // Iterate through all found template file objects.
      foreach ($template_file_objects as $key => $template_file_object) {
        // If the template has not already been overridden by a theme.
        if (!isset($theme_registry[$key]['theme path']) || !preg_match('#/themes/#', $theme_registry[$key]['theme path'])) {
          // Alter the theme path and template elements.
          $theme_registry[$key]['theme path'] = $module_path;
          $theme_registry[$key] = array_merge($theme_registry[$key], $template_file_object);
          $theme_registry[$key]['type'] = 'module';
        }
      }
    }




Create Folder called templates inside your custom module folder.
Copy contrib/quiz/question_types/multichoice/theme/multichoice-alternative.tpl.php file into templates folder with the same name multichoice-alternative.tpl.php.
Clear Cache.
Now you have $form and $fullOptions variables.