JSFiddle - React, Tailwind, and code Playground
HTML
<select id="sel">
<option value="default">Default</option>
</select>
<button id="add">Agregar</button><input type="text" id="opt"><br>
<button id="del">Eliminar</button>
JavaScript
$(function(){
$('#add').on('click', function(){
var opt = $('#opt').val();
$('#sel').prepend('<option value="' + opt + '">' + opt + '</option>');
});
$('#del').on('click', function(){
$('#sel option:selected').remove();
});
});