JSFiddle - React, Tailwind, and code Playground

HTML

<select>
  <option></option>
  <option value="1">Category 1</option>
  <option value="2">Category 2</option>
</select>

<div id="cat1">Category 1</div>
<div id="cat2">Category 2</div>

CSS

body {
  background: #333;
}

div {
  display: none;
}

#cat1 {
  background: magenta;
}

#cat2 {
  background: lightblue;
}

.visible {
  display: block;
}

JavaScript

$('select').change(function(){
	$('.visible').removeClass('visible');
	$('#cat'+$(this).val()+'').addClass('visible');
});