Radio Button Set: more than one Radio Button can be selected at once

Radio Button Set: more than one Radio Button can be selected at once

Would you be kind enough to have a look at this excerpt from my code , please?

I'm trying to write a simple calculator (to calculate the pain suffered by Dementia patients)

You will see that  I'm using radio buttons - because medically, only one value per realm (of pain) is allowable. And that's why I'm using Radio 'Buttons'

I've followed the guidance here as carefully as I can. I've tried looking for similar issues on this forum.

What have I missed?