JSFiddle - React, Tailwind, and code Playground

HTML

<select name="test">
      <option value="1">one</option>
      <option value="2" id="show_div">two</option>
    </select>

<div id="show_block" style="display:none;">it works!</div>

JavaScript

$('select[name="test"]').change(function() {
    if ($(this).find('#show_div').is(':selected')) $('#show_block').show();
});