Use radio buttons for collapsible/collapsed selection

I would suggest using radio buttons for the collapsible/collapsed selction of 'edit groups'. If you only check collapsed the group is not collapsed but rather un-collapsible. I propose three radio selection choices; open (always open, not possible to collapse), collapsible (start open with the ability to collapse) and collapsed (start collapsed and have the ability to expand). The use of radio buttons is more logical as there are only three possiblities and they are mutually exclusive.