How to add scoring system with this type of codes? This is a True or False Game. Answers are very much appreciated. :)

I'm trying to ad a scoring to my simple quiz game. I try to customize my codes but the score always reset to zero when scene loads to another. Thank you for your answers. I'm just a beginner. :)

Here's my code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.SceneManagement;
 using System.Linq;
 
 public class gameManager : MonoBehaviour {
 
     public Question[] questions;
     private static List<Question> unansweredQuestions;
 
     private Question currentQuestion;
 
     [SerializeField]
     private Text factText;
 
     [SerializeField]
     private Text trueAnswerText;
     [SerializeField]
     private Text falseAnswerText;
 
     [SerializeField]
     private Animator animator;
 
     [SerializeField]
     private float timeBetweenQuestions = 2f;
 
     [SerializeField]
     public Text scoreText;
     [SerializeField]
     public Text bestText;
 
     public int scoreCount=0;
     public int bestCount;
 
     public bool scoreIncreasing;
 
     void Start()
     {
 
         if (unansweredQuestions == null || unansweredQuestions.Count == 0) 
         {
             unansweredQuestions = questions.ToList<Question>();
         }
 
         SetCurrentQuestion ();
         Debug.Log (currentQuestion.fact + " is " + currentQuestion.isTrue);
     }
 
     void SetCurrentQuestion ()
     {
         int randomQuestionIndex = Random.Range (0, unansweredQuestions.Count);
         currentQuestion = unansweredQuestions [randomQuestionIndex];
 
 
         factText.text = currentQuestion.fact;
 
         if (currentQuestion.isTrue) 
         {
             trueAnswerText.text = "CORRECT!";
             falseAnswerText.text = "WRONG!";
         } else 
         {
             trueAnswerText.text = "WRONG!";
             falseAnswerText.text = "CORRECT!";
         }
 
 
     }
 
     IEnumerator TransitionToNextQuestion ()
     {
         unansweredQuestions.Remove (currentQuestion);
 
         yield return new WaitForSeconds (timeBetweenQuestions);
         SceneManager.LoadScene (SceneManager.GetActiveScene().buildIndex);
     }
 
 
 
     public void UserSelectTrue ()
     {
         animator.SetTrigger ("True");
         if (currentQuestion.isTrue) {
             Debug.Log ("CORRECT!");
 
         } else 
         {
             Debug.Log ("WRONG!");
         }
         DontDestroyOnLoad (gameObject);
         StartCoroutine (TransitionToNextQuestion ());
     }
 
     public void UserSelectFalse ()
     {
         animator.SetTrigger ("False");
         if (!currentQuestion.isTrue) {
             Debug.Log ("CORRECT!");
 
         } else 
         {
             Debug.Log ("WRONG!");
         }
         DontDestroyOnLoad (gameObject);
         StartCoroutine (TransitionToNextQuestion ());
 
     }
 
     public void LoadScene(string name){
         Application.LoadLevel (name);
     }
 
     public void QuitGame(){
         Application.Quit();
     }
 
         
 }
 

In my code I just initialize the variable for the score. What to do next?