如何使用包含对象列表的对象列表将对象序列化为 JSON 文件？

Question

I am writing simple quiz generator witch will generate quizzes in json format. I have 3 classes as an extra lib to menage all quiz. Those are: Quiz.cs, Question.cs and Answer.cs. I try to serialize Quiz object witch contains list of Questions, witch have 3 fields: question, score and list of Answer objects, but in output i get everything beyond list of answers. My question is how to deal with it and why this is happening.

public class Quiz
    {
        public string Title;
        public string Owner;
        public string Version;
        public string Descryption;
        public List<Double> Wages;
        public List<Question> Questions;
         }

public class Question
    {
        public string Sentance { get; set; }
        public int Score { get; set; }
        List<Answer> answers;
         }

public class Answer
    {
        public string text;
        public bool isTrue;
        }



// creating object Quiz and trying to serialize:

List<Double> wages = new List<Double>();
            wages.Add(1);
            wages.Add(0.5);
            wages.Add(0.2);
Quiz quiz = new Quiz("testowy", "ja", "1.0", "Test quiz for checking serialization",wages);
            List<Answer> tmpAnswers = new List<Answer>();

            tmpAnswers.Add(new Answer("leg", true));
            tmpAnswers.Add(new Answer("eye", false));
            tmpAnswers.Add(new Answer("back", false));
            tmpAnswers.Add(new Answer("chin", false));

            quiz.Questions.Add(new Question("Question 1", 4, tmpAnswers));

            tmpAnswers.Clear();
            tmpAnswers.Add(new Answer("Kasia", false));
            tmpAnswers.Add(new Answer("Andrzej", false));
            tmpAnswers.Add(new Answer("Zenon", true));
            tmpAnswers.Add(new Answer("Buba", false));
            quiz.Questions.Add(new Question("Question 2", 3, tmpAnswers));

            string json = JsonConvert.SerializeObject(quiz, Formatting.Indented);
            Console.WriteLine(json);

//output

{
  "Title": "testowy",
  "Owner": "ja",
  "Version": "1.0",
  "Descryption": "Test quiz for checking serialization",
  "Wages": [
    1.0,
    0.5,
    0.2
  ],
  "Questions": [
    {
      "Sentance": "jaka to jest część ciała?",
      "Score": 4
    },                                // **Missing answers** //
    {
      "Sentance": "Kto to jest?",
      "Score": 3
    }                                // **Missing answers** //
  ]
}

Answer 1

Never mind. Now i see there field list of answers is not public and it have to be for JsonConvert.

public class Question
    {
        public string Sentance { get; set; }
        public int Score { get; set; }
        public List<Answer> answers;            // <----------
         }