Creates a group of radio buttons to answer the question given in the message. Radio buttons are used to allow differentiating between an empty response (Nothing) and a no response (Just False). Consider using the simpler checkBoxField if you don't need to make this distinction.
If this field is optional, the first radio button is labeled "<None>", the second "Yes" and the third "No".
If this field is required, the first radio button is labeled "Yes" and the second "No".
(Exact label titles will depend on localization).