Nested ng-repeat and radio or checkbox inputs not working - angularjs

Question

I am trying to show list of questions and their choices by nested ng-repeat, I have seen plenty of similar questions but still could not fix my issue. My issue here is I could see the list of questions but the choices are not getting displayed and in the developer tools I could only see the commented ng-repeat line in place of choices.
Here is my View
<div ng-repeat ="question in questions track by $index" class="panel panel-default" ng-show="showQuestions">
<div class="panel-heading">
<div class="panel-title">
<a href="div#{{$index}}" class="accordion-toggle" data-toggle="collapse" data-parent="#accordion" >
{{question.QuestionTxt}}
</a>
<div class="row height"></div>
<div class="row" ng-show="question.QuestionTypeTxt == 'RadioButton'">
<div class="col-xs-3" ng-repeat ="answer in questions.QuestionAnswers track by $index">
<input type="radio" ng-model="selectedChoice.choice" ng-value="{{answer.AnswerTxt}}" name="{{question.QuestionTxt}}"/>{{answer.AnswerTxt}}
</div>
</div>
<div class="row" ng-show="question.QuestionTypeTxt == 'Checkbox'">
<div class="col-xs-3" ng-repeat ="answer in questions.QuestionAnswers track by $index">
<input type="checkbox" ng-model="selectedChoice.choice" ng-value="{{answer.AnswerTxt}}" name="{{question.QuestionTxt}}"/>{{answer.AnswerTxt}}
</div>
</div>
</div>
</div>
</div>
Here is my Controller
$scope.questions = [];
$scope.selectedChoice = { choice:"" };
$scope.addQuestions = function () {
$scope.showQuestions = true;
rmat3Service.getQuestionsForSection().then(function (data) {
angular.forEach(data,function(a) {
$scope.questions.push(a);
});
});
}
This is my Json data:
var questions = new List<Question>();
var answers = new List<QuestionAnswer>();
answers.Add(new QuestionAnswer()
{
AnswerTxt = "Yes",
});
answers.Add(new QuestionAnswer()
{
AnswerTxt = "No"
});
answers.Add(new QuestionAnswer()
{
AnswerTxt = "Yes Verified"
});
answers.Add(new QuestionAnswer()
{
AnswerTxt = "Not Applicable"
});
questions.Add(new Question()
{
QuestionId = 1,
QuestionTxt = "Are aisles clear of product on the floor?",
QuestionTypeTxt = "RadioButton",
QuestionAnswers = answers
});
questions.Add(new Question()
{
QuestionId = 2,
QuestionTxt = "Automated Car Wash",
QuestionTypeTxt = "Checkbox",
QuestionAnswers = answers
});
return Json(questions, JsonRequestBehavior.AllowGet);

Answer 1

The issue is that you're attempting to loop questions.QuestionAnswers which doesn't exist. It should be question.QuestionAnswers:
<div class="col-xs-3" ng-repeat ="answer in question.QuestionAnswers track by $index">