JSFiddle - React, Tailwind, and code Playground

HTML

<div id="country">
 <select>
     <option xyz="no-state" value="Germany">Germany</option>
     <option xyz="state" value="USA">USA</option>
     <option xyz="no-state" value="Spain">Spain</option>
 </select>
</div>

<div id="state" style="display:none" >
 <select>
     <option value="Utah">Utah</option>
     <option value="New York">New York</option>
     <option value="California">California</option>
 </select>
</div>

JavaScript

$(document).ready(function(){
    $('#country').change(function() {
       var hasStates = $(this).find("option:selected").attr("xyz");
       if (hasStates == 'no-state')  
       {
        $('div#state').hide();
       }
       else
      {
        $('div#state').show();
      }
    });
});