To format a control, right-click the control, and then select Format Control. In the Format Control dialog box, on the Control tab, you can modify any of the available options: Checked: Displays an option button that is selected. Unchecked: Displays an option button that is cleared.
https://support.microsoft.com/en-us/office/form-controls-9f201e46-8f6b-4a9d-a320-f44b28088cb0

