Radio Buttons help indicate a preference or a selection from amongst a set of selections but they are always used where only one option is allowed to be selected.
There are two main sizes of the Radio button to be used across breakpoints. The larger one usable on Large - Medium screen sizes, while the smaller one for medium to small screen sizes. The minimum padding specs are as follows:
Below is the visualization for all states for the radio button of the size 20px X 20px responsively converts to 16px X 16px, when selected/not selected.
The users can be presented with options in groups as shown below.
Group name
Group name
Group name
Sub Group title 1
Sub Group title 2
The users can be presented with options in a picklist or dropdown menu where the radio button would precede the option description. The visualization is shown below: