If you want to have multiple selections, you should use check-boxes, not
And yes, it is possible to clear all the other fields when one of them is
ticked, using a script.
First, Radio Buttons work like the mechanical station selection buttons on a radio, you can only select one and that button can only be unselected by selecting another button.
You might want to experiment with the 2 types of buttons some with only one with the same name and others where multiple buttons or boxes share the same name and observe what happens.