JSFiddle - React, Tailwind, and code Playground

HTML

<select name='strings' id="strings" multiple style="width:100px;">
    <option value="Test">Test</option>
    <option value="Prof">Prof</option>
    <option value="Live">Live</option>
    <option value="Off">Off</option>
    <option value="On">On</option>
</select>
<select name='strings' id="strings" multiple style="width:100px;">
    <option value="Test">Test</option>
    <option value="Prof">Prof</option>
    <option value="Live">Live</option>
    <option value="Off">Off</option>
    <option value="On">On</option>
</select>

JavaScript

$('#strings option[value=Test]').attr('selected', true);