Array index is out of range

Code should be like this and objects answ1, ans2, ans3, ans4 should be assigned to answerObjects in the editor inspector area.

 public TextMesh[] answerObjects;
  
  void Start () {
  }
  
  public void procedure() {
          //some preceeding code
      int correct = rnd.Next (0, 4);
      int incorrectIndex = 1;
      for (i = 0; i < 4; i++) {
          if (correct == i) {
              answerObjects [i].tag = "correct";
              answerObjects [i].text = answers [0].ToString ();
          } else {
              answerObjects [i].tag = "incorrect";
              answerObjects [i].text = answers [incorrectIndex].ToString();
              incorrectIndex += 1;
          }
      }