JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post">
  <table cellspacing="0" cellpadding="0" border="0" width="100%">
    <tr>
      <td style="padding-left:20px; padding-right:20px">
        <table cellspacing="3" cellpadding="2" border="0" width="100%" class="table">
          <tr>
            <td valign="top">1.</td>
            <td valign="top" class="question" colspan="2">Question</td>
          </tr> 
          <tr>
            <td></td>
            <td width="5"><input value="question1_yes" name="question1" id="question1_yes" type="radio" /></td>
            <td><label for="question1_yes">Yes</label></td>
          </tr>
          <tr>
            <td></td>
            <td><input value="question1_no" name="question1" id="question1_no" type="radio" /></td>
            <td><label for="question1_no">No</label></td>
          </tr>
          <tr>
            <td></td>
            <td><input value="question1_dont_know" name="question1" id="question1_dont_know" type="radio" /></td>
            <td><label for="question1_dont_know">Don't know</label></td>
          </tr>
        </table>
      </td>
    </tr>
    <tr>
      <td style="padding-left:20px; padding-right:20px">
        <table cellspacing="3" cellpadding="2" border="0" width="100%" class="table">
          <tr>
            <td valign="top">2.</td>
            <td valign="top" class="question" colspan="2">Question</td>
          </tr>
          <tr>
            <td></td>
            <td width="5"><input value="question2_yes" name="question2" id="question2_yes" type="radio" /></td>
            <td><label for="question2_yes">Yes</label></td>
          </tr>
          <tr>
            <td></td>
            <td><input value="question2_no" name="question2" id="question2_no" type="radio" /></td>
            <td><label for="question2_no">No</label></td>
          </tr>
          <tr>
            <td></td>
            <td><input value="question2_dont_know" name="question2" id="question2_dont_know" type="radio" /></td>
            <td><label...

JavaScript

$(document).on('submit', 'form', function () {

    var validate = true;
    var unanswered = new Array();

    // Loop through available sets
    $('.table').each(function () {
        // Question text
        var question = $(this).find(".question");
        // Validate
        if (!$(this).find('input').is(':checked')) {
            // Didn't validate ... dispaly alert or do something
            unanswered.push(question.text());
            question.css('color', 'red'); // Highlight unanswered question
            validate = false;
        }
    });

    if (unanswered.length > 0) {
        msg = "Please answer the following questions:\n" + unanswered.join('\n'); 
        alert(msg);
    }
    return validate;
});