Here's an ES6 version, conversion to vanilla JS shouldn't be too hard but I already have jQuery anyways:
function select(options, selected) {_x000D_
return Object.entries(options).reduce((r, [k, v]) => r.append($('<option>').val(k).text(v)), $('<select>')).val(selected);_x000D_
}_x000D_
$('body').append(select({'option1': 'label 1', 'option2': 'label 2'}, 'option2'));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
_x000D_