JSFiddle - React, Tailwind, and code Playground

HTML

<select name="size-unit[0]" class>
      <option value="">Select unit</option>
      <option value="Inches" selected="selected">Inches</option>
      <option value="Centimeters" >Centimeters</option>
      <option value="N/a">N/a</option>
</select>

JavaScript

$('select').val("Centimeters");