js

 let btn = document.getElementById("btn-result");
    let opt_1 = "{{exercise.opt_1}}"
    btn.addEventListener("click",get_result)
    function get_result(){
    const form = document.forms.quiz
    const radios = form.elements.name
    const checked = Array
                 .from(radios)
                 .find(radio => radio.checked).value;
    console.log(opt_1)
    }