Tilføj fieldset/legend, name="superhero" og value til den eksisterende form.
<form>
<h3>Choose your favorite superhero</h3>
<label for="spiderman">
<input type="radio" id="spiderman">
Spider-man
</label>
<label for="superman">
<input type="radio" id="superman">
Superman
</label>
<label for="batman">
<input type="radio" id="batman">
Batman
</label>
<button>Submit</button>
</form> Hints
<form>
<fieldset>
<legend>
<h3>Choose your favorite superhero</h3>
</legend>
<label for="spiderman">
<input name="superhero" value="spiderman" type="radio" id="spiderman">
Spider-man
</label>
<!-- ...resten... -->
</fieldset>
<!-- ... -->
</form>