JSFiddle - React, Tailwind, and code Playground

HTML

<select id="items">
    <option value="One">One</option>
    <option value="Two">Two</option>
    <option value="Three">Three</option>
</select>
<input type="button" id="add" value="Add" />
<select id="result" multiple="multiple" size="5">
</select>

JavaScript

$('#add').click(function(){
    var item = $('#items').val();
    $('#result').append('<option value="' + item + '">' + item + '</option>');
    $('#items>option[value="' + item +'"]').remove();
});