because if some people are introducing the new year and others are saying goodbye to the old year (as it says in the text) then they must be celebrating on the last day of the calender
I think its A or D but I'm not totally sure which one.
Explanation:
The only difference I can see between A and D is if its the last day of the year or the first of the year. I would think it is A, becuase it is going into the New Year, but I am not completely sure.
