Can't drag object references!!

In my text feature in my script, it requires a text reference to be dragged into it in the editor. But i cannot do this, it does not give me the option to when i drag the text reference to the slot. HELP

Script:

  GameObject prefab;
     public float zeoring;
     bool zeoroed400;
     bool zeoroed500;
     int zeoringint400;
     Animator anim;
     bool Sprinting;
     bool rangefinder;
     int rangepress;
     public float distance;
     private int shotsfired;
     public bool running;
     AudioSource audio;
     public AudioClip SniperGunshot;
     public Text Range;
     public Camera GunCam;
     public Camera ScopeCam;
 
 
 void Start()
 {
  RangeText();
 }
 
  void RangeText();
 {
 Range.text = "Zeoring: " + zeoring.ToString();
 }