The choices available may be viewed by pointing and clicking at the down arrow. Move the pointer to your selection and click. A single value will be selected and will then appear in the box. You may select the value by pointing and clicking on the button. The button becomes blackened in when selected.
Radio buttons work as a toggle switch.
To clear a button, point and click. The default is no value selected. The checkbox is similar to the radio button except you will see a small square beside the selection choices. The main difference is that you can check as many values as you would like. You may select a value by pointing and clicking on the checkbox.