Which of these represents the earliest date/time?
D.
To compare times in different time zones, you can subtract the time zone from the time to convert to GMT.
This makes it 02:00 in Berlin because we subtract 1 from 3.
Similarly, it is 02:00 in Helsinki due to subtracting 2 from 4.
Finally, it is 04:00 in Warsaw because we subtracted 1 from 5.
We have a tie because it is the same time in Berlin and Helsinki, so Option D is correct.