Users report that a form is not working. What is the culprit?

<form action="/choices" disabled>
  <fieldset disabled>
    <legend>choices</legend>
    <label>Choice 1 <input type="radio" name="choice" value="choice1" /></label>
    <label>Choice 2 <input type="radio" name="choice" value="choice1" /></label>
    <label>Choice 3 <input type="radio" name="choice" value="choice1" /></label>
    <label>Choice 4 <input type="radio" name="choice" value="choice1" /></label>
    <button>Choose!</button>
  </fieldset>
</form>