If you want to group decisions by radiobuttons or checkboxes you cannot set a group label.
You can do it like that : https://jsfiddle.net/TyrionGraphiste/8res4xmr/1/
There is also an example of this on the documentation

set a group label
These are labels for the individual radio controls, but there is no documentation for how to label the radio group. I've been playing around and can't get the group label to be positioned in a manner consistent with other form labels.
Most helpful comment
These are labels for the individual radio controls, but there is no documentation for how to label the radio group. I've been playing around and can't get the group label to be positioned in a manner consistent with other form labels.