The purpose of this code is to demonstrate that with JavaScript you could enhance a form so that it's possible to tab through all available radio buttons without losing the grouping of typical HTML.
Note: I know that this form will work on browsers without JavaScript but that it'll require much more logic on the back-end to get the selected value—not to mention without JS it'll be possible to select more than one value.
This is a conventional form with regular radio buttons.
The following form uses JavaScript so that you can tab through all the radio buttons.