Radio buttons, also called option buttons, present a set of mutually exclusive choices. You can create individual radio buttons using TRadioButton or use the radio group component (TRadioGroup) to arrange radio buttons into groups automatically. You can group radio buttons to let the user select one from a limited set of choices. See Grouping Controls for more information. 

A selected radio button is displayed as a circle filled in the middle. When not selected, the radio button shows an empty circle. Assign the value True or False to the Checked property to change the radio button's visual state.