Magento 2 How can I show custom options on product list page?

<?php
     $_objectManager = \Magento\Framework\App\ObjectManager::getInstance();

    $customOptions = $_objectManager->get('Magento\Catalog\Model\Product\Option')->getProductOptionCollection($_product);
    $optStr = "";
    foreach($customOptions as $optionKey => $optionVal):
        $optStr .= "<div class='custom-options'><label>".$optionVal->getTitle()." </label>";
            $optStr .= "<select name='options[".$optionVal->getId()."]'>";
            foreach($optionVal->getValues() as $valuesKey => $valuesVal) {
            $optStr .= "<option value='".$valuesVal->getId()."'>".$valuesVal->getTitle()."</option>";
                }

        $optStr .= "</select></div>";
    endforeach;
       echo($optStr );

?>