JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset id="input"><legend>HTML</legend></fieldset>
<fieldset id="output"><legend>Classes left by <code>.removeClass()</code></legend></fieldset>

JavaScript

var html = '<a id="a1" href="#qno1" class="ans mark unmark">1</a>';

jQuery("#input").append( document.createTextNode(html) );
jQuery("#output").append( jQuery( html ).removeClass()[0].className );