function plt_hide_imgopt_menus() {
//Hide the "ImgOPT" menu.
remove_menu_page('imgopt');
//Hide the "ImgOPT → ImgOPT" menu.
remove_submenu_page('imgopt', 'imgopt');
//Hide the "ImgOPT → Settings" menu.
remove_submenu_page('imgopt', 'imgopt-settings');
}
add_action('admin_menu', 'plt_hide_imgopt_menus', 11);