JSFiddle - React, Tailwind, and code Playground

HTML

<select multiple>
    <option>option 1</option>
    <option>option 2</option>
    <option>option 3</option>
    <option>option 4</option>
    <option>option 5</option>
</select>

JavaScript

var myOption = "<option>Dynamic Option</option>";
var index = 2;
$(myOption).insertBefore("select option:nth-child("+index+")");