JSFiddle - React, Tailwind, and code Playground

HTML

<select name="niveau" class="niveau">
    <option value="proposition1">facile</option>
    <option value="proposition2">moyen</option>
    <option value="proposition3">difficile</option>
</select>
<input type="button" name="submit" class="submit" value="Ok" />
<div class="paf"></div>
<script>
    $(function() {
        $('.submit').click(function() {
            var niveau = $('.niveau option:selected').text();
            $('.paf').text(niveau);
        });
    });
</script>