<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<head>
<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
</head>
<h2>Menu de Trabalho</h2>
<body>
<label for="weather">Selecione a função: </label>
<select id="weather">
<option value="">--Selecione uma função--</option>
<option value="1">Cadastrar Automóvel</option>
<option value="2">Cadastrar Pessoa</option>
<option value="3">Cadastrar Venda</option>
<option value="4">Sair</option>
</select>
<p></p>
<script>
var select = document.querySelector('select');
