How can angular or js determine which li and angularul are selected in ul?

How can angular or js determine which li and angularul are selected in ul?

The new company has just received new requirements and made a knowledge base page.

The red color is single-choice blue, and multiple choices are all required to be passed to the background at the beginning. I don't know how to solve this problem. After work, I think of a clever way at home. I don't want to talk about the code.

 

The arrow indicates to write a hidden radio tag in li and bind the id field required by the background to the hidden radio. Just pass the value of the selected radio.