$success = $c->optionsService()->updateReportOptions(
    '/reports/samples/Cascading_multi_select_report',
    array('Country_multi_select' => array('Canada', 'USA'),	'Cascading_state_multi_select' => array('OR', 'WA', 'BC')),
    'CanadaUSA',
    'true');
if ($success) {
   echo "Created new report option successfully";
}