Should checkbox groups or radio button groups have explicit Save buttons?

If there is a settings section with just one setting option via a checkbox or radio button group, should the action taken be saved via an explicit Save button?

My assumption was that a checkbox and a radio button provided enough feedback about the action taken and may not require a Save button. But in case of critical actions, it is always good have additional confirmation from the user.

What are the criteria to consider if the checkboxes or radio buttons should have an explicit Save button?

Please help.