From this script alone, assuming it only exists once;
If you have 4 in the list you will get 1 x “Totale Domande Disponibili: 4”
if you have 8 in the list, you will get 1 x “Totale Domande Disponibili: 8”
This assumes that the list is already populated though. You might want to initialize and populate your list in Awake(), and then use the Count property in Start(). This ensures the list exists and is full before your Debug.Log happens because Start() runs after Awake().