Answer:
You don't have enough information to pick a sure choice. Pick 2 but it might be 1.
Step-by-step explanation:
For me, it would have been dark. Since that word isn't offered, I would pick night.
There definitely is an allusion of some kind. He is reminded of something.
Italy is mentioned, but I think we are to assume it could have happened anywhere. Rome is never mentioned.
Sky is likely a good choice, and it might even be the answer, but I think a better choice is night.