How to align radio buttons within a radio group to be aligned horizontally?

as questioned above, these buttons does not aligned horizontally.
Can anybody help? thanks very much.
I guess maybe I should set the radio button’s alignment one by one,but not sure.
or maybe I misunderstand the logic of alignment itself.

If I remember correctly a selection panel was only designed for vertical alignment. For horizontal alignment you need to use a stack panel.

Thanks for your memory, I 'd try stack panel.