How do I make a form using parsed JSON data?

Question

(I haven't decided what exactly the questions and options are going to be yet). You can see below the parse object I've tried to build the quiz using form. When I try to run this code nothing shows up. What am I doing wrong? I really, really appreciate any help.

const json = 
  { quiz: 
    { q1: { question: 'The question?', options: [ 'option one', 'option two'] , answer: 'The answer' } 
    , q2: { question: 'The question?', options: [ 'option one', 'option two'] , answer: 'The answer' } 
    , q3: { question: 'The question?', options: [ 'option one', 'option two'] , answer: 'The answer' } 
    , q4: { question: 'The question?', options: [ 'option one', 'option two'] , answer: 'The answer' } 
  } } 
  
var obj = JSON.parse(JSON.stringify(json));
console.log(obj);

for (let i = 0; i < obj.quiz.length; i++) {
  document.body.innerHTML +=
    '<h2>' + obj.quiz[i].question + '</h2>'
  document.body.innerHTML +=
    '<form>' + '<input type="radio" name="options" value="option">' + '<label for="option">' + obj.quiz[i].options + '</label>' + '<br>' + '</form>'
}