An option button, also known as a radio button. All objects sharing a single parent that have this attribute are assumed to be part of a single mutually exclusive group. You can use grouped objects to divide option buttons into separate groups when necessary.
items in a mutually exclusive group of options, grouped under a particular heading in dialogue boxes, from which one and only one must always be selected. Based on the old-style radios with pop-out buttons. Appear as circles, which are empty if they are not selected, or have a black dot inside if they are selected. Also called option buttons. (Operated with the arrow cursor keys, short-cut keys.)