Is it possible to erase my answer in a single choice question?

For example:

1) How old are you?

[] 1 - 15
[] 16 - 20
[] 20 - 45

The user answer

1) How old are you?

[] 1 - 15
[X] 16 - 20
[] 20 - 45

But now he wants to erase and doesnt want to mark one

1) How old are you?

[] 1 - 15
[] 16 - 20
[] 20 - 45

Im having this trouble if the field "Tipo de Produto - Winthor" in the form https://form.jotformz.com/71225598854669

THANKS FOR YOUR HELP!!

I have just checked your form and noticed you're using radio buttons for this, please note that a radio button cannot be cleared. 

The easiest way to achieve it would be using a check box instead, but limiting the selection to one. 

You will find the check box field as "Multiple Choice" in the form builder: 

Once the field has been added, open its settings and set the limits under the surveying tab: 

This way if a user does not want to fill a field they can simply un-check the option, the settings should be "Minimum = 0" and "Maximum = 1". 

I hope this helps.