JSFiddle - React, Tailwind, and code Playground

HTML

<select>
  <option value="o1">Option 1</option>
  <option value="o2">Option 2</option>
  <option value="o3">Option 3</option>
  <option value="o4">Option 4</option>
</select>

<div>
  <a href="#" class="o1">Link A</a>
  <a href="#" class="o2">Link B</a>
  <a href="#" class="o3">Link C</a>
  <a href="#" class="o4">Link D</a>
</div>

<div>
  <a href="#" class="o1">Link A</a>
  <a href="#" class="o2">Link B</a>
  <a href="#" class="o3">Link C</a>
  <a href="#" class="o4">Link D</a>
</div>

CSS

.some_class {
  color: #f00;
}

JavaScript

$('select').on('change', function() {
  var mycls = this.value;
  $('a:not(".' + mycls + '")').removeClass('some_class');
  $('a.' + mycls).addClass('some_class');
})