Radio buttons are used when only one item can be selected among a group of items. Radio buttons that share the same name will be grouped together, among which only one can be checked at any given time.
This tutorial demonstrates how to use radio buttons.
Launch Microsoft Word. Type Red, Green and Blue on the document. Choose Add Radio Button from CenoPDF menu. Type color in the Name box. Type red in the Export Value box. Click the OK button. Drag the radio button next to appropriate position.
Follow the same step to create radio buttons for green and blue. Make sure they all use the same name color, but export different values.
Choose Export to PDF from CenoPDF menu and open the PDF file in Adobe Reader. Note that only one radio button can be checked at a time.