Survey Form Radio Button

I dont understand this line of the test

“Every radio button group should have at least 2 radio buttons.”

why there is even a group for the radio button? with the example of survey form link attached, there is only one section using it

this one,
“Would you recommend freeCodeCamp to a friend?”

please help me to solve this?

thank you

Please edit your post and share your code and the step link